Accounting

limit · query

Maximum number of items to return.

{
  "type": "integer",
  "minimum": 1,
  "maximum": 200,
  "default": 50
}

after · query

Mapping identifier returned as nextCursor by the previous page.

{
  "description": "Opaque tenant-owned account mapping revision identifier.",
  "type": "string",
  "pattern": "^map_[0-9A-HJKMNP-TV-Z]{26}$"
}

200 · application/json

Mapping revisions in version order.

Required fields: data

{
  "description": "Mapping revision identities in ascending version order.",
  "type": "object",
  "required": [
    "data"
  ],
  "additionalProperties": false,
  "properties": {
    "data": {
      "type": "array",
      "items": {
        "description": "Published revision identity and content digest.",
        "type": "object",
        "required": [
          "id",
          "version",
          "digest",
          "createdAt"
        ],
        "additionalProperties": false,
        "properties": {
          "id": {
            "description": "Opaque tenant-owned account mapping revision identifier.",
            "type": "string",
            "pattern": "^map_[0-9A-HJKMNP-TV-Z]{26}$"
          },
          "version": {
            "type": "integer",
            "format": "int64",
            "minimum": 1
          },
          "digest": {
            "type": "string",
            "pattern": "^sha256:[0-9a-f]{64}$"
          },
          "createdAt": {
            "type": "string",
            "format": "date-time"
          }
        }
      }
    },
    "nextCursor": {
      "description": "Opaque tenant-owned account mapping revision identifier.",
      "type": "string",
      "pattern": "^map_[0-9A-HJKMNP-TV-Z]{26}$"
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

application/json · required

Required fields: items

{
  "description": "Complete classification revision, subject also to the global mutation body byte limit.",
  "type": "object",
  "required": [
    "items"
  ],
  "additionalProperties": false,
  "properties": {
    "items": {
      "type": "array",
      "minItems": 1,
      "maxItems": 10000,
      "items": {
        "description": "Consumer-selected classification and report section for one account.",
        "type": "object",
        "required": [
          "accountId",
          "classification",
          "reportCode",
          "reportName"
        ],
        "additionalProperties": false,
        "properties": {
          "accountId": {
            "type": "string",
            "description": "Opaque account identifier.",
            "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
            "examples": [
              "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
            ]
          },
          "classification": {
            "description": "Explicit consumer classification for financial reporting.",
            "type": "string",
            "enum": [
              "asset",
              "liability",
              "equity",
              "income",
              "expense"
            ]
          },
          "reportCode": {
            "type": "string",
            "minLength": 1,
            "maxLength": 64
          },
          "reportName": {
            "type": "string",
            "minLength": 1,
            "maxLength": 200
          }
        }
      }
    }
  }
}

201 · application/json

Immutable mapping revision.

Required fields: id, version, digest, createdAt, items

{
  "description": "A complete immutable tenant-owned account mapping.",
  "type": "object",
  "required": [
    "id",
    "version",
    "digest",
    "createdAt",
    "items"
  ],
  "additionalProperties": false,
  "properties": {
    "id": {
      "description": "Opaque tenant-owned account mapping revision identifier.",
      "type": "string",
      "pattern": "^map_[0-9A-HJKMNP-TV-Z]{26}$"
    },
    "version": {
      "type": "integer",
      "format": "int64",
      "minimum": 1
    },
    "digest": {
      "type": "string",
      "pattern": "^sha256:[0-9a-f]{64}$"
    },
    "createdAt": {
      "type": "string",
      "format": "date-time"
    },
    "items": {
      "type": "array",
      "items": {
        "description": "Immutable classification and account labels frozen at publication.",
        "type": "object",
        "required": [
          "accountId",
          "accountNo",
          "accountName",
          "classification",
          "reportCode",
          "reportName"
        ],
        "additionalProperties": false,
        "properties": {
          "accountId": {
            "type": "string",
            "description": "Opaque account identifier.",
            "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
            "examples": [
              "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
            ]
          },
          "accountNo": {
            "type": "string"
          },
          "accountName": {
            "type": "string"
          },
          "classification": {
            "description": "Explicit consumer classification for financial reporting.",
            "type": "string",
            "enum": [
              "asset",
              "liability",
              "equity",
              "income",
              "expense"
            ]
          },
          "reportCode": {
            "type": "string"
          },
          "reportName": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

mappingId · path · required

Opaque tenant-owned account mapping revision identifier.

{
  "description": "Opaque tenant-owned account mapping revision identifier.",
  "type": "string",
  "pattern": "^map_[0-9A-HJKMNP-TV-Z]{26}$"
}

200 · application/json

Immutable mapping revision with its complete account items.

Required fields: id, version, digest, createdAt, items

{
  "description": "A complete immutable tenant-owned account mapping.",
  "type": "object",
  "required": [
    "id",
    "version",
    "digest",
    "createdAt",
    "items"
  ],
  "additionalProperties": false,
  "properties": {
    "id": {
      "description": "Opaque tenant-owned account mapping revision identifier.",
      "type": "string",
      "pattern": "^map_[0-9A-HJKMNP-TV-Z]{26}$"
    },
    "version": {
      "type": "integer",
      "format": "int64",
      "minimum": 1
    },
    "digest": {
      "type": "string",
      "pattern": "^sha256:[0-9a-f]{64}$"
    },
    "createdAt": {
      "type": "string",
      "format": "date-time"
    },
    "items": {
      "type": "array",
      "items": {
        "description": "Immutable classification and account labels frozen at publication.",
        "type": "object",
        "required": [
          "accountId",
          "accountNo",
          "accountName",
          "classification",
          "reportCode",
          "reportName"
        ],
        "additionalProperties": false,
        "properties": {
          "accountId": {
            "type": "string",
            "description": "Opaque account identifier.",
            "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
            "examples": [
              "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
            ]
          },
          "accountNo": {
            "type": "string"
          },
          "accountName": {
            "type": "string"
          },
          "classification": {
            "description": "Explicit consumer classification for financial reporting.",
            "type": "string",
            "enum": [
              "asset",
              "liability",
              "equity",
              "income",
              "expense"
            ]
          },
          "reportCode": {
            "type": "string"
          },
          "reportName": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

limit · query

Maximum number of items to return.

{
  "type": "integer",
  "minimum": 1,
  "maximum": 200,
  "default": 50
}

after · query

Return items after this account — the `nextCursor` of the previous page.

{
  "type": "string",
  "description": "Opaque account identifier.",
  "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

200 · application/json

A page of accounts.

Required fields: data

{
  "type": "object",
  "description": "One page of accounts, oldest Kontonummer first.",
  "required": [
    "data"
  ],
  "additionalProperties": false,
  "properties": {
    "data": {
      "type": "array",
      "items": {
        "type": "object",
        "description": "A Konto in the tenant's chart of accounts.",
        "required": [
          "id",
          "accountNo",
          "name",
          "createdAt"
        ],
        "additionalProperties": false,
        "properties": {
          "retiredAt": {
            "description": "Retirement prevents new ordinary postings; historical Storno remains available.",
            "type": [
              "string",
              "null"
            ],
            "format": "date-time"
          },
          "id": {
            "type": "string",
            "description": "Opaque account identifier.",
            "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
            "examples": [
              "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
            ]
          },
          "accountNo": {
            "type": "string",
            "description": "Kontonummer within the tenant's chart of accounts.",
            "examples": [
              "1200"
            ]
          },
          "name": {
            "type": "string",
            "examples": [
              "Bank"
            ]
          },
          "accountType": {
            "type": [
              "string",
              "null"
            ],
            "description": "Optional account classification supplied by the consumer."
          },
          "createdAt": {
            "type": "string",
            "format": "date-time"
          }
        }
      }
    },
    "nextCursor": {
      "type": "string",
      "description": "Opaque account identifier.",
      "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

application/json · required

Required fields: accountNo, name

{
  "type": "object",
  "description": "Fields accepted when adding a Konto.",
  "required": [
    "accountNo",
    "name"
  ],
  "additionalProperties": false,
  "properties": {
    "accountNo": {
      "type": "string",
      "minLength": 1,
      "maxLength": 32,
      "examples": [
        "1200"
      ]
    },
    "name": {
      "type": "string",
      "minLength": 1,
      "maxLength": 200,
      "examples": [
        "Bank"
      ]
    },
    "accountType": {
      "type": [
        "string",
        "null"
      ],
      "maxLength": 64
    }
  }
}

201 · application/json

The created account.

Required fields: id, accountNo, name, createdAt

{
  "type": "object",
  "description": "A Konto in the tenant's chart of accounts.",
  "required": [
    "id",
    "accountNo",
    "name",
    "createdAt"
  ],
  "additionalProperties": false,
  "properties": {
    "retiredAt": {
      "description": "Retirement prevents new ordinary postings; historical Storno remains available.",
      "type": [
        "string",
        "null"
      ],
      "format": "date-time"
    },
    "id": {
      "type": "string",
      "description": "Opaque account identifier.",
      "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "accountNo": {
      "type": "string",
      "description": "Kontonummer within the tenant's chart of accounts.",
      "examples": [
        "1200"
      ]
    },
    "name": {
      "type": "string",
      "examples": [
        "Bank"
      ]
    },
    "accountType": {
      "type": [
        "string",
        "null"
      ],
      "description": "Optional account classification supplied by the consumer."
    },
    "createdAt": {
      "type": "string",
      "format": "date-time"
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

accountId · path · required

Identifier of the account, as returned when it was created.

{
  "type": "string",
  "description": "Opaque account identifier.",
  "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

200 · application/json

The account.

Required fields: id, accountNo, name, createdAt

{
  "type": "object",
  "description": "A Konto in the tenant's chart of accounts.",
  "required": [
    "id",
    "accountNo",
    "name",
    "createdAt"
  ],
  "additionalProperties": false,
  "properties": {
    "retiredAt": {
      "description": "Retirement prevents new ordinary postings; historical Storno remains available.",
      "type": [
        "string",
        "null"
      ],
      "format": "date-time"
    },
    "id": {
      "type": "string",
      "description": "Opaque account identifier.",
      "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "accountNo": {
      "type": "string",
      "description": "Kontonummer within the tenant's chart of accounts.",
      "examples": [
        "1200"
      ]
    },
    "name": {
      "type": "string",
      "examples": [
        "Bank"
      ]
    },
    "accountType": {
      "type": [
        "string",
        "null"
      ],
      "description": "Optional account classification supplied by the consumer."
    },
    "createdAt": {
      "type": "string",
      "format": "date-time"
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

accountId · path · required

Identifier of the account, as returned when it was created.

{
  "type": "string",
  "description": "Opaque account identifier.",
  "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

asOf · query

Inclusive posted-entry cutoff; omit for latest, or reuse a prior response's asOf.

{
  "type": "string",
  "description": "A posted tenant entry's public ID, or empty for the permanent zero cutoff.",
  "pattern": "^(empty|je_[0-9A-HJKMNP-TV-Z]{26})$",
  "examples": [
    "empty"
  ]
}

currency · query

Restrict to one currency without conversion; omit to include each separately.

{
  "type": "string",
  "description": "ISO-4217 alphabetic currency code.",
  "pattern": "^[A-Z]{3}$",
  "examples": [
    "EUR"
  ]
}

bookingDateFrom · query

Inclusive earliest booking date for movements; earlier history forms openingBalance.

{
  "type": "string",
  "format": "date"
}

bookingDateTo · query

Inclusive latest booking date; must not precede bookingDateFrom.

{
  "type": "string",
  "format": "date"
}

200 · application/json

Exact totals per currency at the returned posting snapshot.

Required fields: accountId, asOf, data

{
  "type": "object",
  "description": "Per-currency balances at a fixed posting cutoff; no currency conversion.",
  "required": [
    "accountId",
    "asOf",
    "data"
  ],
  "additionalProperties": false,
  "properties": {
    "accountId": {
      "type": "string",
      "description": "Opaque account identifier.",
      "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "asOf": {
      "type": "string",
      "description": "A posted tenant entry's public ID, or empty for the permanent zero cutoff.",
      "pattern": "^(empty|je_[0-9A-HJKMNP-TV-Z]{26})$",
      "examples": [
        "empty"
      ]
    },
    "data": {
      "type": "array",
      "items": {
        "type": "object",
        "description": "Exact debit/credit totals and signed balances in one currency.",
        "required": [
          "currency",
          "openingBalance",
          "debitTotal",
          "creditTotal",
          "closingBalance"
        ],
        "additionalProperties": false,
        "properties": {
          "currency": {
            "type": "string",
            "description": "ISO-4217 alphabetic currency code.",
            "pattern": "^[A-Z]{3}$",
            "examples": [
              "EUR"
            ]
          },
          "openingBalance": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          },
          "debitTotal": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          },
          "creditTotal": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          },
          "closingBalance": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          }
        }
      }
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

403 · application/problem+json

The caller is authenticated for the tenant but lacks the explicit permission required for this operation. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

accountId · path · required

Identifier of the account, as returned when it was created.

{
  "type": "string",
  "description": "Opaque account identifier.",
  "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

200 · application/json

Retired account (stable on repeated retirement).

Required fields: id, accountNo, name, createdAt

{
  "type": "object",
  "description": "A Konto in the tenant's chart of accounts.",
  "required": [
    "id",
    "accountNo",
    "name",
    "createdAt"
  ],
  "additionalProperties": false,
  "properties": {
    "retiredAt": {
      "description": "Retirement prevents new ordinary postings; historical Storno remains available.",
      "type": [
        "string",
        "null"
      ],
      "format": "date-time"
    },
    "id": {
      "type": "string",
      "description": "Opaque account identifier.",
      "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "accountNo": {
      "type": "string",
      "description": "Kontonummer within the tenant's chart of accounts.",
      "examples": [
        "1200"
      ]
    },
    "name": {
      "type": "string",
      "examples": [
        "Bank"
      ]
    },
    "accountType": {
      "type": [
        "string",
        "null"
      ],
      "description": "Optional account classification supplied by the consumer."
    },
    "createdAt": {
      "type": "string",
      "format": "date-time"
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

accountId · path · required

Identifier of the account, as returned when it was created.

{
  "type": "string",
  "description": "Opaque account identifier.",
  "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

limit · query

Maximum number of items to return.

{
  "type": "integer",
  "minimum": 1,
  "maximum": 200,
  "default": 50
}

asOf · query

Inclusive posted-entry cutoff; omit for latest, or reuse a prior response's asOf.

{
  "type": "string",
  "description": "A posted tenant entry's public ID, or empty for the permanent zero cutoff.",
  "pattern": "^(empty|je_[0-9A-HJKMNP-TV-Z]{26})$",
  "examples": [
    "empty"
  ]
}

currency · query

Restrict to one currency without conversion; omit to include each separately.

{
  "type": "string",
  "description": "ISO-4217 alphabetic currency code.",
  "pattern": "^[A-Z]{3}$",
  "examples": [
    "EUR"
  ]
}

bookingDateFrom · query

Inclusive earliest booking date for movements; earlier history forms openingBalance.

{
  "type": "string",
  "format": "date"
}

bookingDateTo · query

Inclusive latest booking date; must not precede bookingDateFrom.

{
  "type": "string",
  "format": "date"
}

after · query

Opaque nextCursor from this account and the same date/currency filters.

{
  "type": "string",
  "description": "Opaque position including the posting snapshot; pass unchanged as after.",
  "maxLength": 73,
  "examples": [
    "v1:je_9GXQ8W5V4R3P2N1M0KJHGF7ED6:je_9GXQ8W5V4R3P2N1M0KJHGF7ED6:1"
  ]
}

200 · application/json

A page of immutable posted account movements.

Required fields: accountId, asOf, data

{
  "type": "object",
  "description": "A bounded page of posted lines at one stable booking cutoff.",
  "required": [
    "accountId",
    "asOf",
    "data"
  ],
  "additionalProperties": false,
  "properties": {
    "accountId": {
      "type": "string",
      "description": "Opaque account identifier.",
      "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "asOf": {
      "type": "string",
      "description": "A posted tenant entry's public ID, or empty for the permanent zero cutoff.",
      "pattern": "^(empty|je_[0-9A-HJKMNP-TV-Z]{26})$",
      "examples": [
        "empty"
      ]
    },
    "data": {
      "type": "array",
      "items": {
        "type": "object",
        "description": "One immutable posted line for the requested account.",
        "required": [
          "entryId",
          "seq",
          "lineNo",
          "bookingDate",
          "periodId",
          "accountNo",
          "side",
          "amount",
          "taxKey"
        ],
        "additionalProperties": false,
        "properties": {
          "taxRuleId": {
            "type": "string",
            "maxLength": 128,
            "description": "Optional immutable published rule; requires matching taxKey and effective booking date."
          },
          "bookingText": {
            "type": [
              "string",
              "null"
            ],
            "minLength": 1,
            "maxLength": 500,
            "description": "Buchungstext, preserved exactly and immutable once posted. Null or omitted means absent; U+0000 is forbidden."
          },
          "externalReference": {
            "type": [
              "string",
              "null"
            ],
            "minLength": 1,
            "maxLength": 255,
            "description": "Caller business reference, preserved exactly and immutable once posted. Not unique; use Idempotency-Key for retries. Null or omitted means absent; U+0000 is forbidden."
          },
          "entryId": {
            "type": "string",
            "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
            "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
            "examples": [
              "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
            ]
          },
          "seq": {
            "type": "integer",
            "format": "int64",
            "minimum": 1,
            "description": "The Buchungsnummer shared by every line in this entry."
          },
          "lineNo": {
            "type": "integer",
            "minimum": 1,
            "description": "Original position in the journal entry, not a page offset."
          },
          "bookingDate": {
            "type": "string",
            "format": "date"
          },
          "periodId": {
            "type": "string",
            "description": "Opaque period identifier.",
            "pattern": "^per_[0-9A-HJKMNP-TV-Z]{26}$",
            "examples": [
              "per_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
            ]
          },
          "accountNo": {
            "type": "string",
            "description": "Frozen Kontonummer as booked."
          },
          "side": {
            "type": "string",
            "description": "Buchungsseite — Soll (debit) or Haben (credit).",
            "enum": [
              "debit",
              "credit"
            ]
          },
          "amount": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          },
          "taxKey": {
            "type": [
              "string",
              "null"
            ]
          },
          "reversalOf": {
            "type": "string",
            "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
            "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
            "examples": [
              "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
            ]
          }
        }
      }
    },
    "nextCursor": {
      "type": "string",
      "description": "Opaque position including the posting snapshot; pass unchanged as after.",
      "maxLength": 73,
      "examples": [
        "v1:je_9GXQ8W5V4R3P2N1M0KJHGF7ED6:je_9GXQ8W5V4R3P2N1M0KJHGF7ED6:1"
      ]
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

403 · application/problem+json

The caller is authenticated for the tenant but lacks the explicit permission required for this operation. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

preservationId · path · required

Identifier of the durable document preservation request.

{
  "type": "string",
  "description": "Opaque durable preservation-request identifier.",
  "pattern": "^prsv_[0-9A-HJKMNP-TV-Z]{26}$"
}

200 · application/json

The tenant-visible request and its application state.

Required fields: id, documentId, requestedBy, requestedAt, reason, legalHold, status

{
  "description": "An immutable preservation decision and its durable execution status.",
  "type": "object",
  "required": [
    "id",
    "documentId",
    "requestedBy",
    "requestedAt",
    "reason",
    "legalHold",
    "status"
  ],
  "additionalProperties": false,
  "properties": {
    "id": {
      "type": "string",
      "description": "Opaque durable preservation-request identifier.",
      "pattern": "^prsv_[0-9A-HJKMNP-TV-Z]{26}$"
    },
    "documentId": {
      "type": "string",
      "description": "Opaque Beleg identifier. It does not encode storage identity.",
      "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "requestedBy": {
      "type": "string",
      "description": "Opaque public membership identifier.",
      "pattern": "^mem_[0-9A-HJKMNP-TV-Z]{26}$"
    },
    "requestedAt": {
      "type": "string",
      "format": "date-time"
    },
    "reason": {
      "type": "string",
      "minLength": 1,
      "maxLength": 1000
    },
    "retainUntil": {
      "type": "string",
      "format": "date-time",
      "description": "Requested exclusive retention deadline, absent for a hold-only request."
    },
    "legalHold": {
      "type": "boolean",
      "description": "True requests a legal hold ON. False does not request any hold change."
    },
    "status": {
      "type": "string",
      "enum": [
        "pending",
        "applied"
      ],
      "x-enum-varnames": [
        "DocumentPreservationStatusPending",
        "DocumentPreservationStatusApplied"
      ]
    },
    "nextAttemptAt": {
      "type": "string",
      "format": "date-time",
      "description": "Earliest scheduled retry after a storage or verification failure."
    },
    "failureCode": {
      "type": "string",
      "enum": [
        "archive-unavailable",
        "source-integrity-mismatch",
        "protection-unconfirmed"
      ],
      "description": "Last retry reason. No provider errors or storage coordinates are exposed."
    },
    "appliedAt": {
      "type": "string",
      "format": "date-time",
      "description": "Time confirmed protection was committed to the audit record."
    },
    "observedRetainUntil": {
      "type": "string",
      "format": "date-time",
      "description": "Confirmed COMPLIANCE deadline, at least the requested protection."
    },
    "observedLegalHold": {
      "type": "boolean",
      "description": "Legal hold observed when the request was applied."
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

403 · application/problem+json

The caller is authenticated for the tenant but lacks the explicit permission required for this operation. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

limit · query

Maximum number of items to return.

{
  "type": "integer",
  "minimum": 1,
  "maximum": 200,
  "default": 50
}

after · query

The nextCursor from the previous page.

{
  "type": "string",
  "description": "Opaque Beleg identifier. It does not encode storage identity.",
  "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

status · query

Restrict to pending or archived documents.

{
  "type": "string",
  "description": "`pending` awaits a verified direct or server-owned write; `archived` names\nan immutable, Object-Locked version whose evidence is sealed in the archive.\n",
  "enum": [
    "pending",
    "archived"
  ]
}

origin · query

Restrict to uploaded originals or generated derivatives.

{
  "type": "string",
  "description": "`uploaded` is an original caller-provided Beleg. `derived` is a new immutable\nserver-produced Beleg whose exact source lineage is retained independently.\n",
  "enum": [
    "uploaded",
    "derived"
  ]
}

documentDateFrom · query

Inclusive earliest Belegdatum.

{
  "type": "string",
  "format": "date"
}

documentDateTo · query

Inclusive latest Belegdatum; must not precede documentDateFrom.

{
  "type": "string",
  "format": "date"
}

journalEntryId · query

Only documents directly linked to this tenant's Buchung.

{
  "type": "string",
  "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
  "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

sourceDocumentId · query

Only direct derivatives of this tenant's source document.

{
  "type": "string",
  "description": "Opaque Beleg identifier. It does not encode storage identity.",
  "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

200 · application/json

A page of public document metadata.

Required fields: data

{
  "type": "object",
  "description": "One page in immutable document-ID order; not a snapshot across requests.",
  "required": [
    "data"
  ],
  "additionalProperties": false,
  "properties": {
    "data": {
      "type": "array",
      "items": {
        "type": "object",
        "description": "Public metadata for an immutable Beleg declaration.",
        "required": [
          "id",
          "origin",
          "status",
          "originalFilename",
          "mediaType",
          "sizeBytes",
          "contentSha256",
          "documentDate",
          "classification",
          "retentionUntil",
          "createdAt",
          "archivedAt"
        ],
        "additionalProperties": false,
        "properties": {
          "id": {
            "type": "string",
            "description": "Opaque Beleg identifier. It does not encode storage identity.",
            "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
            "examples": [
              "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
            ]
          },
          "origin": {
            "type": "string",
            "description": "`uploaded` is an original caller-provided Beleg. `derived` is a new immutable\nserver-produced Beleg whose exact source lineage is retained independently.\n",
            "enum": [
              "uploaded",
              "derived"
            ]
          },
          "status": {
            "type": "string",
            "description": "`pending` awaits a verified direct or server-owned write; `archived` names\nan immutable, Object-Locked version whose evidence is sealed in the archive.\n",
            "enum": [
              "pending",
              "archived"
            ]
          },
          "originalFilename": {
            "type": "string"
          },
          "mediaType": {
            "type": "string"
          },
          "sizeBytes": {
            "type": "integer",
            "format": "int64",
            "minimum": 1
          },
          "contentSha256": {
            "type": "string",
            "pattern": "^[0-9a-f]{64}$"
          },
          "documentDate": {
            "type": "string",
            "format": "date"
          },
          "classification": {
            "type": "string",
            "description": "Trusted server-assigned Beleg class; never caller-selected."
          },
          "retentionUntil": {
            "type": "string",
            "format": "date",
            "description": "Inclusive legal retention date selected by the server."
          },
          "createdAt": {
            "type": "string",
            "format": "date-time"
          },
          "archivedAt": {
            "type": [
              "string",
              "null"
            ],
            "format": "date-time"
          }
        }
      }
    },
    "nextCursor": {
      "type": "string",
      "description": "Opaque Beleg identifier. It does not encode storage identity.",
      "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

403 · application/problem+json

The caller is authenticated for the tenant but lacks the explicit permission required for this operation. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

application/json · required

Required fields: originalFilename, mediaType, sizeBytes, contentSha256, documentDate

{
  "type": "object",
  "description": "Caller-known immutable metadata for a Buchungsbeleg upload.",
  "required": [
    "originalFilename",
    "mediaType",
    "sizeBytes",
    "contentSha256",
    "documentDate"
  ],
  "additionalProperties": false,
  "properties": {
    "originalFilename": {
      "type": "string",
      "minLength": 1,
      "description": "A UTF-8 basename of at most 255 bytes, never a path.",
      "examples": [
        "rechnung-2026-0042.pdf"
      ]
    },
    "mediaType": {
      "type": "string",
      "minLength": 3,
      "description": "Canonical media type covered by the upload signature, at most 255\nUTF-8 bytes.\n",
      "examples": [
        "application/pdf"
      ]
    },
    "sizeBytes": {
      "type": "integer",
      "format": "int64",
      "minimum": 1,
      "description": "Exact content length in bytes.",
      "examples": [
        48192
      ]
    },
    "contentSha256": {
      "type": "string",
      "pattern": "^[0-9a-f]{64}$",
      "description": "Exact SHA-256 digest in canonical lowercase hexadecimal.",
      "examples": [
        "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
      ]
    },
    "documentDate": {
      "type": "string",
      "format": "date",
      "description": "Belegdatum used to select the versioned retention policy."
    }
  }
}

201 · application/json

The pending Beleg and its first direct-upload request.

Required fields: document, upload

{
  "type": "object",
  "description": "A pending Beleg plus its first direct-upload request.",
  "required": [
    "document",
    "upload"
  ],
  "additionalProperties": false,
  "properties": {
    "document": {
      "type": "object",
      "description": "Public metadata for an immutable Beleg declaration.",
      "required": [
        "id",
        "origin",
        "status",
        "originalFilename",
        "mediaType",
        "sizeBytes",
        "contentSha256",
        "documentDate",
        "classification",
        "retentionUntil",
        "createdAt",
        "archivedAt"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "type": "string",
          "description": "Opaque Beleg identifier. It does not encode storage identity.",
          "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "origin": {
          "type": "string",
          "description": "`uploaded` is an original caller-provided Beleg. `derived` is a new immutable\nserver-produced Beleg whose exact source lineage is retained independently.\n",
          "enum": [
            "uploaded",
            "derived"
          ]
        },
        "status": {
          "type": "string",
          "description": "`pending` awaits a verified direct or server-owned write; `archived` names\nan immutable, Object-Locked version whose evidence is sealed in the archive.\n",
          "enum": [
            "pending",
            "archived"
          ]
        },
        "originalFilename": {
          "type": "string"
        },
        "mediaType": {
          "type": "string"
        },
        "sizeBytes": {
          "type": "integer",
          "format": "int64",
          "minimum": 1
        },
        "contentSha256": {
          "type": "string",
          "pattern": "^[0-9a-f]{64}$"
        },
        "documentDate": {
          "type": "string",
          "format": "date"
        },
        "classification": {
          "type": "string",
          "description": "Trusted server-assigned Beleg class; never caller-selected."
        },
        "retentionUntil": {
          "type": "string",
          "format": "date",
          "description": "Inclusive legal retention date selected by the server."
        },
        "createdAt": {
          "type": "string",
          "format": "date-time"
        },
        "archivedAt": {
          "type": [
            "string",
            "null"
          ],
          "format": "date-time"
        }
      }
    },
    "upload": {
      "type": "object",
      "description": "Short-lived exact HTTP request for a direct immutable upload.",
      "required": [
        "url",
        "method",
        "headers",
        "expiresAt"
      ],
      "additionalProperties": false,
      "properties": {
        "url": {
          "type": "string",
          "format": "uri",
          "description": "Signed destination. Treat it as a secret until it expires."
        },
        "method": {
          "type": "string",
          "const": "PUT"
        },
        "headers": {
          "type": "object",
          "description": "Every header must be sent with the exact returned value.",
          "additionalProperties": {
            "type": "string"
          }
        },
        "expiresAt": {
          "type": "string",
          "format": "date-time"
        }
      }
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

documentId · path · required

Identifier of the Beleg.

{
  "type": "string",
  "description": "Opaque Beleg identifier. It does not encode storage identity.",
  "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

200 · application/json

The Beleg.

Required fields: id, origin, status, originalFilename, mediaType, sizeBytes, contentSha256, documentDate, classification, retentionUntil, createdAt, archivedAt

{
  "type": "object",
  "description": "Public metadata for an immutable Beleg declaration.",
  "required": [
    "id",
    "origin",
    "status",
    "originalFilename",
    "mediaType",
    "sizeBytes",
    "contentSha256",
    "documentDate",
    "classification",
    "retentionUntil",
    "createdAt",
    "archivedAt"
  ],
  "additionalProperties": false,
  "properties": {
    "id": {
      "type": "string",
      "description": "Opaque Beleg identifier. It does not encode storage identity.",
      "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "origin": {
      "type": "string",
      "description": "`uploaded` is an original caller-provided Beleg. `derived` is a new immutable\nserver-produced Beleg whose exact source lineage is retained independently.\n",
      "enum": [
        "uploaded",
        "derived"
      ]
    },
    "status": {
      "type": "string",
      "description": "`pending` awaits a verified direct or server-owned write; `archived` names\nan immutable, Object-Locked version whose evidence is sealed in the archive.\n",
      "enum": [
        "pending",
        "archived"
      ]
    },
    "originalFilename": {
      "type": "string"
    },
    "mediaType": {
      "type": "string"
    },
    "sizeBytes": {
      "type": "integer",
      "format": "int64",
      "minimum": 1
    },
    "contentSha256": {
      "type": "string",
      "pattern": "^[0-9a-f]{64}$"
    },
    "documentDate": {
      "type": "string",
      "format": "date"
    },
    "classification": {
      "type": "string",
      "description": "Trusted server-assigned Beleg class; never caller-selected."
    },
    "retentionUntil": {
      "type": "string",
      "format": "date",
      "description": "Inclusive legal retention date selected by the server."
    },
    "createdAt": {
      "type": "string",
      "format": "date-time"
    },
    "archivedAt": {
      "type": [
        "string",
        "null"
      ],
      "format": "date-time"
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

documentId · path · required

Identifier of the Beleg.

{
  "type": "string",
  "description": "Opaque Beleg identifier. It does not encode storage identity.",
  "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

200 · application/json

The archived Beleg.

Required fields: id, origin, status, originalFilename, mediaType, sizeBytes, contentSha256, documentDate, classification, retentionUntil, createdAt, archivedAt

{
  "type": "object",
  "description": "Public metadata for an immutable Beleg declaration.",
  "required": [
    "id",
    "origin",
    "status",
    "originalFilename",
    "mediaType",
    "sizeBytes",
    "contentSha256",
    "documentDate",
    "classification",
    "retentionUntil",
    "createdAt",
    "archivedAt"
  ],
  "additionalProperties": false,
  "properties": {
    "id": {
      "type": "string",
      "description": "Opaque Beleg identifier. It does not encode storage identity.",
      "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "origin": {
      "type": "string",
      "description": "`uploaded` is an original caller-provided Beleg. `derived` is a new immutable\nserver-produced Beleg whose exact source lineage is retained independently.\n",
      "enum": [
        "uploaded",
        "derived"
      ]
    },
    "status": {
      "type": "string",
      "description": "`pending` awaits a verified direct or server-owned write; `archived` names\nan immutable, Object-Locked version whose evidence is sealed in the archive.\n",
      "enum": [
        "pending",
        "archived"
      ]
    },
    "originalFilename": {
      "type": "string"
    },
    "mediaType": {
      "type": "string"
    },
    "sizeBytes": {
      "type": "integer",
      "format": "int64",
      "minimum": 1
    },
    "contentSha256": {
      "type": "string",
      "pattern": "^[0-9a-f]{64}$"
    },
    "documentDate": {
      "type": "string",
      "format": "date"
    },
    "classification": {
      "type": "string",
      "description": "Trusted server-assigned Beleg class; never caller-selected."
    },
    "retentionUntil": {
      "type": "string",
      "format": "date",
      "description": "Inclusive legal retention date selected by the server."
    },
    "createdAt": {
      "type": "string",
      "format": "date-time"
    },
    "archivedAt": {
      "type": [
        "string",
        "null"
      ],
      "format": "date-time"
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

documentId · path · required

Identifier of the Beleg.

{
  "type": "string",
  "description": "Opaque Beleg identifier. It does not encode storage identity.",
  "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

200 · application/octet-stream

The verified original bytes, downloaded as an attachment.

{
  "type": "string",
  "format": "binary"
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

403 · application/problem+json

The caller is authenticated for the tenant but lacks the explicit permission required for this operation. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

410 · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

502 · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

503 · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

documentId · path · required

Identifier of the Beleg.

{
  "type": "string",
  "description": "Opaque Beleg identifier. It does not encode storage identity.",
  "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

202 · application/json

The validation was durably queued, or an exact idempotent replay.

{
  "description": "Durable validation state. Branch on `status` before reading terminal\nfields: `pending` has neither result nor failure, `completed` has exactly\none result, and `failed` has exactly one public failure code.\n",
  "oneOf": [
    {
      "type": "object",
      "description": "A durable validation waiting for processing or a retry.",
      "required": [
        "id",
        "documentId",
        "status",
        "requestedAt"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "type": "string",
          "description": "Opaque durable e-invoice validation identifier.",
          "pattern": "^eiv_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "eiv_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "documentId": {
          "type": "string",
          "description": "Opaque Beleg identifier. It does not encode storage identity.",
          "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "status": {
          "type": "string",
          "const": "pending",
          "x-enum-varnames": [
            "EInvoiceValidationPendingStatusPending"
          ]
        },
        "requestedAt": {
          "type": "string",
          "format": "date-time"
        }
      }
    },
    {
      "type": "object",
      "description": "A terminal validation, whether the invoice is valid or invalid.",
      "required": [
        "id",
        "documentId",
        "status",
        "requestedAt",
        "completedAt",
        "result"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "type": "string",
          "description": "Opaque durable e-invoice validation identifier.",
          "pattern": "^eiv_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "eiv_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "documentId": {
          "type": "string",
          "description": "Opaque Beleg identifier. It does not encode storage identity.",
          "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "status": {
          "type": "string",
          "const": "completed",
          "x-enum-varnames": [
            "EInvoiceValidationCompletedStatusCompleted"
          ]
        },
        "requestedAt": {
          "type": "string",
          "format": "date-time"
        },
        "completedAt": {
          "type": "string",
          "format": "date-time"
        },
        "result": {
          "type": "object",
          "description": "Terminal result for the exact archived source. Validator and ruleset\nversions are opaque identities reported under the pinned standalone-platform\npolicy, never guessed by this service.\n",
          "required": [
            "schema",
            "sourceSha256",
            "valid",
            "syntax",
            "validator",
            "ruleset",
            "issues"
          ],
          "additionalProperties": false,
          "properties": {
            "schema": {
              "type": "string",
              "const": "devacc.einvoice.validation.v1",
              "x-enum-varnames": [
                "EInvoiceValidationResultSchemaV1"
              ]
            },
            "sourceSha256": {
              "type": "string",
              "pattern": "^[0-9a-f]{64}$",
              "description": "SHA-256 of the exact immutable source version that was validated."
            },
            "valid": {
              "type": "boolean",
              "description": "False is a completed validation outcome, not a processing error."
            },
            "syntax": {
              "type": "string",
              "enum": [
                "ubl",
                "cii",
                "unknown"
              ],
              "x-enum-varnames": [
                "EInvoiceValidationSyntaxUBL",
                "EInvoiceValidationSyntaxCII",
                "EInvoiceValidationSyntaxUnknown"
              ],
              "description": "Canonical syntax classification. `valid: true` is only possible for\n`ubl` or `cii`; `unknown` is retained only for invalid outcomes.\n"
            },
            "profile": {
              "type": "string",
              "minLength": 1,
              "maxLength": 2048,
              "description": "Optional non-empty profile identity of at most 2,048 UTF-8 bytes."
            },
            "validator": {
              "type": "object",
              "description": "Opaque processor runtime or versioned compliance-artifact identity.",
              "required": [
                "name",
                "version"
              ],
              "additionalProperties": false,
              "properties": {
                "name": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256,
                  "description": "Non-empty identity of at most 256 UTF-8 bytes."
                },
                "version": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256,
                  "description": "Non-empty opaque version of at most 256 UTF-8 bytes."
                }
              }
            },
            "ruleset": {
              "type": "object",
              "description": "Opaque processor runtime or versioned compliance-artifact identity.",
              "required": [
                "name",
                "version"
              ],
              "additionalProperties": false,
              "properties": {
                "name": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256,
                  "description": "Non-empty identity of at most 256 UTF-8 bytes."
                },
                "version": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256,
                  "description": "Non-empty opaque version of at most 256 UTF-8 bytes."
                }
              }
            },
            "issues": {
              "type": "array",
              "maxItems": 1000,
              "items": {
                "type": "object",
                "description": "One structured validator finding.",
                "required": [
                  "severity",
                  "code",
                  "message"
                ],
                "additionalProperties": false,
                "properties": {
                  "severity": {
                    "type": "string",
                    "enum": [
                      "error",
                      "warning",
                      "information"
                    ],
                    "x-enum-varnames": [
                      "EInvoiceValidationIssueSeverityError",
                      "EInvoiceValidationIssueSeverityWarning",
                      "EInvoiceValidationIssueSeverityInformation"
                    ]
                  },
                  "code": {
                    "type": "string",
                    "minLength": 1,
                    "maxLength": 256,
                    "description": "Non-empty stable finding code of at most 256 UTF-8 bytes."
                  },
                  "message": {
                    "type": "string",
                    "minLength": 1,
                    "maxLength": 8192,
                    "description": "Non-empty finding text of at most 8,192 UTF-8 bytes."
                  },
                  "location": {
                    "type": "string",
                    "minLength": 1,
                    "maxLength": 8192,
                    "description": "Optional non-empty source location of at most 8,192 UTF-8 bytes."
                  }
                }
              }
            }
          }
        }
      }
    },
    {
      "type": "object",
      "description": "A terminal validation processing failure without sensitive diagnostics.",
      "required": [
        "id",
        "documentId",
        "status",
        "requestedAt",
        "completedAt",
        "failure"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "type": "string",
          "description": "Opaque durable e-invoice validation identifier.",
          "pattern": "^eiv_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "eiv_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "documentId": {
          "type": "string",
          "description": "Opaque Beleg identifier. It does not encode storage identity.",
          "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "status": {
          "type": "string",
          "const": "failed",
          "x-enum-varnames": [
            "EInvoiceValidationFailedStatusFailed"
          ]
        },
        "requestedAt": {
          "type": "string",
          "format": "date-time"
        },
        "completedAt": {
          "type": "string",
          "format": "date-time"
        },
        "failure": {
          "type": "object",
          "description": "Stable public failure classification; internal diagnostics are private.",
          "required": [
            "code"
          ],
          "additionalProperties": false,
          "properties": {
            "code": {
              "type": "string",
              "const": "validation-processing-failed",
              "x-enum-varnames": [
                "EInvoiceValidationFailureCodeValidationProcessingFailed"
              ]
            }
          }
        }
      }
    }
  ],
  "discriminator": {
    "propertyName": "status",
    "mapping": {
      "pending": "#/components/schemas/EInvoiceValidationPending",
      "completed": "#/components/schemas/EInvoiceValidationCompleted",
      "failed": "#/components/schemas/EInvoiceValidationFailed"
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

documentId · path · required

Identifier of the Beleg.

{
  "type": "string",
  "description": "Opaque Beleg identifier. It does not encode storage identity.",
  "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

application/json · required

Required fields: reason

{
  "type": "object",
  "required": [
    "reason"
  ],
  "minProperties": 2,
  "additionalProperties": false,
  "description": "Supply retainUntil, legalHold=true, or both, with a nonblank reason without\nleading or trailing whitespace. retainUntil is an exclusive whole-second\nUTC deadline, in the future and later than all accepted retention decisions.\nTo preserve through a calendar day, use the following day's UTC midnight.\n",
  "properties": {
    "reason": {
      "type": "string",
      "minLength": 1,
      "maxLength": 1000
    },
    "retainUntil": {
      "type": "string",
      "format": "date-time",
      "pattern": "^[0-9]{4}-[0-9]{2}-[0-9]{2}T[0-9]{2}:[0-9]{2}:[0-9]{2}(Z|[+-]00:00)$"
    },
    "legalHold": {
      "type": "boolean",
      "const": true
    }
  }
}

202 · application/json

The durable preservation request, awaiting storage confirmation.

Required fields: id, documentId, requestedBy, requestedAt, reason, legalHold, status

{
  "description": "An immutable preservation decision and its durable execution status.",
  "type": "object",
  "required": [
    "id",
    "documentId",
    "requestedBy",
    "requestedAt",
    "reason",
    "legalHold",
    "status"
  ],
  "additionalProperties": false,
  "properties": {
    "id": {
      "type": "string",
      "description": "Opaque durable preservation-request identifier.",
      "pattern": "^prsv_[0-9A-HJKMNP-TV-Z]{26}$"
    },
    "documentId": {
      "type": "string",
      "description": "Opaque Beleg identifier. It does not encode storage identity.",
      "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "requestedBy": {
      "type": "string",
      "description": "Opaque public membership identifier.",
      "pattern": "^mem_[0-9A-HJKMNP-TV-Z]{26}$"
    },
    "requestedAt": {
      "type": "string",
      "format": "date-time"
    },
    "reason": {
      "type": "string",
      "minLength": 1,
      "maxLength": 1000
    },
    "retainUntil": {
      "type": "string",
      "format": "date-time",
      "description": "Requested exclusive retention deadline, absent for a hold-only request."
    },
    "legalHold": {
      "type": "boolean",
      "description": "True requests a legal hold ON. False does not request any hold change."
    },
    "status": {
      "type": "string",
      "enum": [
        "pending",
        "applied"
      ],
      "x-enum-varnames": [
        "DocumentPreservationStatusPending",
        "DocumentPreservationStatusApplied"
      ]
    },
    "nextAttemptAt": {
      "type": "string",
      "format": "date-time",
      "description": "Earliest scheduled retry after a storage or verification failure."
    },
    "failureCode": {
      "type": "string",
      "enum": [
        "archive-unavailable",
        "source-integrity-mismatch",
        "protection-unconfirmed"
      ],
      "description": "Last retry reason. No provider errors or storage coordinates are exposed."
    },
    "appliedAt": {
      "type": "string",
      "format": "date-time",
      "description": "Time confirmed protection was committed to the audit record."
    },
    "observedRetainUntil": {
      "type": "string",
      "format": "date-time",
      "description": "Confirmed COMPLIANCE deadline, at least the requested protection."
    },
    "observedLegalHold": {
      "type": "boolean",
      "description": "Legal hold observed when the request was applied."
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

403 · application/problem+json

The caller is authenticated for the tenant but lacks the explicit permission required for this operation. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

documentId · path · required

Identifier of the Beleg.

{
  "type": "string",
  "description": "Opaque Beleg identifier. It does not encode storage identity.",
  "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

200 · application/json

The complete, bounded set of direct source references.

Required fields: data

{
  "type": "object",
  "description": "All direct sources; empty for an uploaded original.",
  "required": [
    "data"
  ],
  "additionalProperties": false,
  "properties": {
    "data": {
      "type": "array",
      "maxItems": 2,
      "items": {
        "type": "object",
        "description": "One immutable edge from a generated Beleg to its direct source.",
        "required": [
          "documentId",
          "role",
          "kind"
        ],
        "additionalProperties": false,
        "properties": {
          "documentId": {
            "type": "string",
            "description": "Opaque Beleg identifier. It does not encode storage identity.",
            "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
            "examples": [
              "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
            ]
          },
          "role": {
            "type": "string",
            "description": "The source's role in generating the output.",
            "enum": [
              "invoice",
              "visual"
            ]
          },
          "kind": {
            "type": "string",
            "description": "The transformation which produced the requested output.",
            "enum": [
              "zugferd-pdf"
            ]
          }
        }
      }
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

403 · application/problem+json

The caller is authenticated for the tenant but lacks the explicit permission required for this operation. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

documentId · path · required

Identifier of the Beleg.

{
  "type": "string",
  "description": "Opaque Beleg identifier. It does not encode storage identity.",
  "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

200 · application/json

A fresh short-lived direct-upload request.

Required fields: url, method, headers, expiresAt

{
  "type": "object",
  "description": "Short-lived exact HTTP request for a direct immutable upload.",
  "required": [
    "url",
    "method",
    "headers",
    "expiresAt"
  ],
  "additionalProperties": false,
  "properties": {
    "url": {
      "type": "string",
      "format": "uri",
      "description": "Signed destination. Treat it as a secret until it expires."
    },
    "method": {
      "type": "string",
      "const": "PUT"
    },
    "headers": {
      "type": "object",
      "description": "Every header must be sent with the exact returned value.",
      "additionalProperties": {
        "type": "string"
      }
    },
    "expiresAt": {
      "type": "string",
      "format": "date-time"
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

validationId · path · required

Identifier of the durable e-invoice validation request.

{
  "type": "string",
  "description": "Opaque durable e-invoice validation identifier.",
  "pattern": "^eiv_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "eiv_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

200 · application/json

The validation request and its current state.

{
  "description": "Durable validation state. Branch on `status` before reading terminal\nfields: `pending` has neither result nor failure, `completed` has exactly\none result, and `failed` has exactly one public failure code.\n",
  "oneOf": [
    {
      "type": "object",
      "description": "A durable validation waiting for processing or a retry.",
      "required": [
        "id",
        "documentId",
        "status",
        "requestedAt"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "type": "string",
          "description": "Opaque durable e-invoice validation identifier.",
          "pattern": "^eiv_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "eiv_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "documentId": {
          "type": "string",
          "description": "Opaque Beleg identifier. It does not encode storage identity.",
          "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "status": {
          "type": "string",
          "const": "pending",
          "x-enum-varnames": [
            "EInvoiceValidationPendingStatusPending"
          ]
        },
        "requestedAt": {
          "type": "string",
          "format": "date-time"
        }
      }
    },
    {
      "type": "object",
      "description": "A terminal validation, whether the invoice is valid or invalid.",
      "required": [
        "id",
        "documentId",
        "status",
        "requestedAt",
        "completedAt",
        "result"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "type": "string",
          "description": "Opaque durable e-invoice validation identifier.",
          "pattern": "^eiv_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "eiv_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "documentId": {
          "type": "string",
          "description": "Opaque Beleg identifier. It does not encode storage identity.",
          "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "status": {
          "type": "string",
          "const": "completed",
          "x-enum-varnames": [
            "EInvoiceValidationCompletedStatusCompleted"
          ]
        },
        "requestedAt": {
          "type": "string",
          "format": "date-time"
        },
        "completedAt": {
          "type": "string",
          "format": "date-time"
        },
        "result": {
          "type": "object",
          "description": "Terminal result for the exact archived source. Validator and ruleset\nversions are opaque identities reported under the pinned standalone-platform\npolicy, never guessed by this service.\n",
          "required": [
            "schema",
            "sourceSha256",
            "valid",
            "syntax",
            "validator",
            "ruleset",
            "issues"
          ],
          "additionalProperties": false,
          "properties": {
            "schema": {
              "type": "string",
              "const": "devacc.einvoice.validation.v1",
              "x-enum-varnames": [
                "EInvoiceValidationResultSchemaV1"
              ]
            },
            "sourceSha256": {
              "type": "string",
              "pattern": "^[0-9a-f]{64}$",
              "description": "SHA-256 of the exact immutable source version that was validated."
            },
            "valid": {
              "type": "boolean",
              "description": "False is a completed validation outcome, not a processing error."
            },
            "syntax": {
              "type": "string",
              "enum": [
                "ubl",
                "cii",
                "unknown"
              ],
              "x-enum-varnames": [
                "EInvoiceValidationSyntaxUBL",
                "EInvoiceValidationSyntaxCII",
                "EInvoiceValidationSyntaxUnknown"
              ],
              "description": "Canonical syntax classification. `valid: true` is only possible for\n`ubl` or `cii`; `unknown` is retained only for invalid outcomes.\n"
            },
            "profile": {
              "type": "string",
              "minLength": 1,
              "maxLength": 2048,
              "description": "Optional non-empty profile identity of at most 2,048 UTF-8 bytes."
            },
            "validator": {
              "type": "object",
              "description": "Opaque processor runtime or versioned compliance-artifact identity.",
              "required": [
                "name",
                "version"
              ],
              "additionalProperties": false,
              "properties": {
                "name": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256,
                  "description": "Non-empty identity of at most 256 UTF-8 bytes."
                },
                "version": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256,
                  "description": "Non-empty opaque version of at most 256 UTF-8 bytes."
                }
              }
            },
            "ruleset": {
              "type": "object",
              "description": "Opaque processor runtime or versioned compliance-artifact identity.",
              "required": [
                "name",
                "version"
              ],
              "additionalProperties": false,
              "properties": {
                "name": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256,
                  "description": "Non-empty identity of at most 256 UTF-8 bytes."
                },
                "version": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256,
                  "description": "Non-empty opaque version of at most 256 UTF-8 bytes."
                }
              }
            },
            "issues": {
              "type": "array",
              "maxItems": 1000,
              "items": {
                "type": "object",
                "description": "One structured validator finding.",
                "required": [
                  "severity",
                  "code",
                  "message"
                ],
                "additionalProperties": false,
                "properties": {
                  "severity": {
                    "type": "string",
                    "enum": [
                      "error",
                      "warning",
                      "information"
                    ],
                    "x-enum-varnames": [
                      "EInvoiceValidationIssueSeverityError",
                      "EInvoiceValidationIssueSeverityWarning",
                      "EInvoiceValidationIssueSeverityInformation"
                    ]
                  },
                  "code": {
                    "type": "string",
                    "minLength": 1,
                    "maxLength": 256,
                    "description": "Non-empty stable finding code of at most 256 UTF-8 bytes."
                  },
                  "message": {
                    "type": "string",
                    "minLength": 1,
                    "maxLength": 8192,
                    "description": "Non-empty finding text of at most 8,192 UTF-8 bytes."
                  },
                  "location": {
                    "type": "string",
                    "minLength": 1,
                    "maxLength": 8192,
                    "description": "Optional non-empty source location of at most 8,192 UTF-8 bytes."
                  }
                }
              }
            }
          }
        }
      }
    },
    {
      "type": "object",
      "description": "A terminal validation processing failure without sensitive diagnostics.",
      "required": [
        "id",
        "documentId",
        "status",
        "requestedAt",
        "completedAt",
        "failure"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "type": "string",
          "description": "Opaque durable e-invoice validation identifier.",
          "pattern": "^eiv_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "eiv_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "documentId": {
          "type": "string",
          "description": "Opaque Beleg identifier. It does not encode storage identity.",
          "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "status": {
          "type": "string",
          "const": "failed",
          "x-enum-varnames": [
            "EInvoiceValidationFailedStatusFailed"
          ]
        },
        "requestedAt": {
          "type": "string",
          "format": "date-time"
        },
        "completedAt": {
          "type": "string",
          "format": "date-time"
        },
        "failure": {
          "type": "object",
          "description": "Stable public failure classification; internal diagnostics are private.",
          "required": [
            "code"
          ],
          "additionalProperties": false,
          "properties": {
            "code": {
              "type": "string",
              "const": "validation-processing-failed",
              "x-enum-varnames": [
                "EInvoiceValidationFailureCodeValidationProcessingFailed"
              ]
            }
          }
        }
      }
    }
  ],
  "discriminator": {
    "propertyName": "status",
    "mapping": {
      "pending": "#/components/schemas/EInvoiceValidationPending",
      "completed": "#/components/schemas/EInvoiceValidationCompleted",
      "failed": "#/components/schemas/EInvoiceValidationFailed"
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

validationId · path · required

Identifier of the durable e-invoice validation request.

{
  "type": "string",
  "description": "Opaque durable e-invoice validation identifier.",
  "pattern": "^eiv_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "eiv_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

application/json · required

Required fields: visualDocumentId

{
  "type": "object",
  "description": "The immutable PDF visual source to combine with validated CII XML.",
  "required": [
    "visualDocumentId"
  ],
  "additionalProperties": false,
  "properties": {
    "visualDocumentId": {
      "type": "string",
      "description": "Opaque Beleg identifier. It does not encode storage identity.",
      "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    }
  }
}

202 · application/json

The generation was durably queued. An exact Idempotency-Key replay returns its originally stored response; the same semantic request under a new key returns the already existing durable resource in its current state, which may already be terminal.

{
  "description": "Durable ZUGFeRD PDF state. Pending has neither result nor failure;\ncompleted has the new immutable output Beleg and exact generation evidence;\nfailed exposes only a stable public failure code.\n",
  "oneOf": [
    {
      "type": "object",
      "description": "A durable generation waiting for processing or a retry.",
      "required": [
        "id",
        "validationId",
        "invoiceDocumentId",
        "visualDocumentId",
        "target",
        "recipe",
        "status",
        "requestedAt"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "type": "string",
          "description": "Opaque durable ZUGFeRD PDF generation identifier.",
          "pattern": "^eip_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "eip_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "validationId": {
          "type": "string",
          "description": "Opaque durable e-invoice validation identifier.",
          "pattern": "^eiv_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "eiv_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "invoiceDocumentId": {
          "type": "string",
          "description": "Opaque Beleg identifier. It does not encode storage identity.",
          "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "visualDocumentId": {
          "type": "string",
          "description": "Opaque Beleg identifier. It does not encode storage identity.",
          "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "target": {
          "type": "object",
          "description": "Frozen standard and profile selected by trusted server configuration.",
          "required": [
            "name",
            "version",
            "profile"
          ],
          "additionalProperties": false,
          "properties": {
            "name": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            },
            "version": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            },
            "profile": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            }
          }
        },
        "recipe": {
          "type": "object",
          "description": "Frozen versioned generation recipe selected by trusted server configuration.",
          "required": [
            "name",
            "version"
          ],
          "additionalProperties": false,
          "properties": {
            "name": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            },
            "version": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            }
          }
        },
        "status": {
          "type": "string",
          "const": "pending",
          "x-enum-varnames": [
            "ZUGFeRDPDFPendingStatusPending"
          ]
        },
        "requestedAt": {
          "type": "string",
          "format": "date-time"
        }
      }
    },
    {
      "type": "object",
      "description": "A terminal generation with immutable output and provenance evidence.",
      "required": [
        "id",
        "validationId",
        "invoiceDocumentId",
        "visualDocumentId",
        "target",
        "recipe",
        "status",
        "requestedAt",
        "completedAt",
        "outputDocument",
        "result"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "type": "string",
          "description": "Opaque durable ZUGFeRD PDF generation identifier.",
          "pattern": "^eip_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "eip_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "validationId": {
          "type": "string",
          "description": "Opaque durable e-invoice validation identifier.",
          "pattern": "^eiv_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "eiv_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "invoiceDocumentId": {
          "type": "string",
          "description": "Opaque Beleg identifier. It does not encode storage identity.",
          "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "visualDocumentId": {
          "type": "string",
          "description": "Opaque Beleg identifier. It does not encode storage identity.",
          "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "target": {
          "type": "object",
          "description": "Frozen standard and profile selected by trusted server configuration.",
          "required": [
            "name",
            "version",
            "profile"
          ],
          "additionalProperties": false,
          "properties": {
            "name": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            },
            "version": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            },
            "profile": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            }
          }
        },
        "recipe": {
          "type": "object",
          "description": "Frozen versioned generation recipe selected by trusted server configuration.",
          "required": [
            "name",
            "version"
          ],
          "additionalProperties": false,
          "properties": {
            "name": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            },
            "version": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            }
          }
        },
        "status": {
          "type": "string",
          "const": "completed",
          "x-enum-varnames": [
            "ZUGFeRDPDFCompletedStatusCompleted"
          ]
        },
        "requestedAt": {
          "type": "string",
          "format": "date-time"
        },
        "completedAt": {
          "type": "string",
          "format": "date-time"
        },
        "outputDocument": {
          "type": "object",
          "description": "Public metadata for the completed generation output. This Beleg is always\na newly derived, immutable archived PDF; its exact two-source lineage is\nretained server-side.\n",
          "required": [
            "id",
            "origin",
            "status",
            "originalFilename",
            "mediaType",
            "sizeBytes",
            "contentSha256",
            "documentDate",
            "classification",
            "retentionUntil",
            "createdAt",
            "archivedAt"
          ],
          "additionalProperties": false,
          "properties": {
            "id": {
              "type": "string",
              "description": "Opaque Beleg identifier. It does not encode storage identity.",
              "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
              "examples": [
                "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
              ]
            },
            "origin": {
              "type": "string",
              "const": "derived",
              "x-enum-varnames": [
                "ZUGFeRDPDFDocumentOriginDerived"
              ]
            },
            "status": {
              "type": "string",
              "const": "archived",
              "x-enum-varnames": [
                "ZUGFeRDPDFDocumentStatusArchived"
              ]
            },
            "originalFilename": {
              "type": "string"
            },
            "mediaType": {
              "type": "string",
              "const": "application/pdf",
              "x-enum-varnames": [
                "ZUGFeRDPDFDocumentMediaTypeApplicationPDF"
              ]
            },
            "sizeBytes": {
              "type": "integer",
              "format": "int64",
              "minimum": 1
            },
            "contentSha256": {
              "type": "string",
              "pattern": "^[0-9a-f]{64}$"
            },
            "documentDate": {
              "type": "string",
              "format": "date"
            },
            "classification": {
              "type": "string",
              "description": "Trusted server-assigned Beleg class."
            },
            "retentionUntil": {
              "type": "string",
              "format": "date"
            },
            "createdAt": {
              "type": "string",
              "format": "date-time"
            },
            "archivedAt": {
              "type": "string",
              "format": "date-time"
            }
          }
        },
        "result": {
          "type": "object",
          "description": "Exact immutable generation evidence reported by the sidecar.",
          "required": [
            "schema",
            "invoiceSha256",
            "visualSha256",
            "output",
            "standard",
            "recipe",
            "processor",
            "ruleset"
          ],
          "additionalProperties": false,
          "properties": {
            "schema": {
              "type": "string",
              "const": "devacc.einvoice.zugferd-pdf.v1",
              "x-enum-varnames": [
                "ZUGFeRDPDFResultSchemaV1"
              ]
            },
            "invoiceSha256": {
              "type": "string",
              "pattern": "^[0-9a-f]{64}$"
            },
            "visualSha256": {
              "type": "string",
              "pattern": "^[0-9a-f]{64}$"
            },
            "output": {
              "type": "object",
              "description": "Exact output facts verified before the derived Beleg was archived.",
              "required": [
                "contentId",
                "mediaType",
                "sizeBytes",
                "sha256",
                "pdfConformance",
                "embeddedFilename"
              ],
              "additionalProperties": false,
              "properties": {
                "contentId": {
                  "type": "string",
                  "const": "output",
                  "x-enum-varnames": [
                    "ZUGFeRDPDFOutputContentIdOutput"
                  ]
                },
                "mediaType": {
                  "type": "string",
                  "const": "application/pdf",
                  "x-enum-varnames": [
                    "ZUGFeRDPDFOutputMediaTypeApplicationPDF"
                  ]
                },
                "sizeBytes": {
                  "type": "integer",
                  "format": "int64",
                  "minimum": 1
                },
                "sha256": {
                  "type": "string",
                  "pattern": "^[0-9a-f]{64}$"
                },
                "pdfConformance": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256,
                  "description": "Conformance identity reported by the configured production sidecar.\nThis API records the evidence but does not independently certify it.\n"
                },
                "embeddedFilename": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 255
                }
              }
            },
            "standard": {
              "type": "object",
              "description": "Frozen standard and profile selected by trusted server configuration.",
              "required": [
                "name",
                "version",
                "profile"
              ],
              "additionalProperties": false,
              "properties": {
                "name": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256
                },
                "version": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256
                },
                "profile": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256
                }
              }
            },
            "recipe": {
              "type": "object",
              "description": "Frozen versioned generation recipe selected by trusted server configuration.",
              "required": [
                "name",
                "version"
              ],
              "additionalProperties": false,
              "properties": {
                "name": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256
                },
                "version": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256
                }
              }
            },
            "processor": {
              "type": "object",
              "description": "Opaque ZUGFeRD sidecar runtime or versioned artifact identity.",
              "required": [
                "name",
                "version"
              ],
              "additionalProperties": false,
              "properties": {
                "name": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256
                },
                "version": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256
                }
              }
            },
            "ruleset": {
              "type": "object",
              "description": "Opaque ZUGFeRD sidecar runtime or versioned artifact identity.",
              "required": [
                "name",
                "version"
              ],
              "additionalProperties": false,
              "properties": {
                "name": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256
                },
                "version": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256
                }
              }
            }
          }
        }
      }
    },
    {
      "type": "object",
      "description": "A terminal PDF-generation failure without sensitive diagnostics.",
      "required": [
        "id",
        "validationId",
        "invoiceDocumentId",
        "visualDocumentId",
        "target",
        "recipe",
        "status",
        "requestedAt",
        "completedAt",
        "failure"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "type": "string",
          "description": "Opaque durable ZUGFeRD PDF generation identifier.",
          "pattern": "^eip_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "eip_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "validationId": {
          "type": "string",
          "description": "Opaque durable e-invoice validation identifier.",
          "pattern": "^eiv_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "eiv_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "invoiceDocumentId": {
          "type": "string",
          "description": "Opaque Beleg identifier. It does not encode storage identity.",
          "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "visualDocumentId": {
          "type": "string",
          "description": "Opaque Beleg identifier. It does not encode storage identity.",
          "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "target": {
          "type": "object",
          "description": "Frozen standard and profile selected by trusted server configuration.",
          "required": [
            "name",
            "version",
            "profile"
          ],
          "additionalProperties": false,
          "properties": {
            "name": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            },
            "version": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            },
            "profile": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            }
          }
        },
        "recipe": {
          "type": "object",
          "description": "Frozen versioned generation recipe selected by trusted server configuration.",
          "required": [
            "name",
            "version"
          ],
          "additionalProperties": false,
          "properties": {
            "name": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            },
            "version": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            }
          }
        },
        "status": {
          "type": "string",
          "const": "failed",
          "x-enum-varnames": [
            "ZUGFeRDPDFFailedStatusFailed"
          ]
        },
        "requestedAt": {
          "type": "string",
          "format": "date-time"
        },
        "completedAt": {
          "type": "string",
          "format": "date-time"
        },
        "failure": {
          "type": "object",
          "description": "Stable public failure classification without internal diagnostics.",
          "required": [
            "code"
          ],
          "additionalProperties": false,
          "properties": {
            "code": {
              "type": "string",
              "enum": [
                "unsupported-source",
                "generation-capacity-exceeded"
              ],
              "x-enum-varnames": [
                "ZUGFeRDPDFFailureCodeUnsupportedSource",
                "ZUGFeRDPDFFailureCodeGenerationCapacityExceeded"
              ]
            }
          }
        }
      }
    }
  ],
  "discriminator": {
    "propertyName": "status",
    "mapping": {
      "pending": "#/components/schemas/ZUGFeRDPDFPending",
      "completed": "#/components/schemas/ZUGFeRDPDFCompleted",
      "failed": "#/components/schemas/ZUGFeRDPDFFailed"
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

200 · application/zip

The complete verified ZIP, downloaded as an attachment.

{
  "type": "string",
  "format": "binary"
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

403 · application/problem+json

The caller is authenticated for the tenant but lacks the explicit permission required for this operation. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

413 · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

502 · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

503 · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

limit · query

Maximum number of items to return.

{
  "type": "integer",
  "minimum": 1,
  "maximum": 200,
  "default": 50
}

after · query

Fiscal-year ID returned as nextCursor by the preceding page.

{
  "type": "string",
  "description": "Opaque fiscal-year identifier.",
  "pattern": "^fy_[0-9A-HJKMNP-TV-Z]{26}$"
}

200 · application/json

One page of fiscal years.

Required fields: data

{
  "type": "object",
  "description": "One page of fiscal years.",
  "required": [
    "data"
  ],
  "additionalProperties": false,
  "properties": {
    "data": {
      "type": "array",
      "items": {
        "type": "object",
        "description": "Tenant fiscal year and its finalization state.",
        "required": [
          "id",
          "label",
          "startsOn",
          "endsOn",
          "status",
          "createdAt"
        ],
        "additionalProperties": false,
        "properties": {
          "id": {
            "type": "string",
            "description": "Opaque fiscal-year identifier.",
            "pattern": "^fy_[0-9A-HJKMNP-TV-Z]{26}$"
          },
          "label": {
            "type": "string"
          },
          "startsOn": {
            "type": "string",
            "format": "date"
          },
          "endsOn": {
            "type": "string",
            "format": "date"
          },
          "status": {
            "type": "string",
            "enum": [
              "open",
              "finalized"
            ],
            "x-enum-varnames": [
              "FiscalYearStatusOpen",
              "FiscalYearStatusFinalized"
            ],
            "description": "Finalized years cannot be changed."
          },
          "finalizedAt": {
            "type": [
              "string",
              "null"
            ],
            "format": "date-time"
          },
          "createdAt": {
            "type": "string",
            "format": "date-time"
          }
        }
      }
    },
    "nextCursor": {
      "type": "string",
      "description": "Opaque fiscal-year identifier.",
      "pattern": "^fy_[0-9A-HJKMNP-TV-Z]{26}$"
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

application/json · required

Required fields: label, startsOn, endsOn

{
  "type": "object",
  "description": "Inclusive fiscal-year date range chosen by the consumer.",
  "required": [
    "label",
    "startsOn",
    "endsOn"
  ],
  "additionalProperties": false,
  "properties": {
    "label": {
      "type": "string",
      "minLength": 1,
      "maxLength": 64
    },
    "startsOn": {
      "type": "string",
      "format": "date"
    },
    "endsOn": {
      "type": "string",
      "format": "date"
    }
  }
}

201 · application/json

The created fiscal year.

Required fields: id, label, startsOn, endsOn, status, createdAt

{
  "type": "object",
  "description": "Tenant fiscal year and its finalization state.",
  "required": [
    "id",
    "label",
    "startsOn",
    "endsOn",
    "status",
    "createdAt"
  ],
  "additionalProperties": false,
  "properties": {
    "id": {
      "type": "string",
      "description": "Opaque fiscal-year identifier.",
      "pattern": "^fy_[0-9A-HJKMNP-TV-Z]{26}$"
    },
    "label": {
      "type": "string"
    },
    "startsOn": {
      "type": "string",
      "format": "date"
    },
    "endsOn": {
      "type": "string",
      "format": "date"
    },
    "status": {
      "type": "string",
      "enum": [
        "open",
        "finalized"
      ],
      "x-enum-varnames": [
        "FiscalYearStatusOpen",
        "FiscalYearStatusFinalized"
      ],
      "description": "Finalized years cannot be changed."
    },
    "finalizedAt": {
      "type": [
        "string",
        "null"
      ],
      "format": "date-time"
    },
    "createdAt": {
      "type": "string",
      "format": "date-time"
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

yearId · path · required

Opaque fiscal-year identifier.

{
  "type": "string",
  "description": "Opaque fiscal-year identifier.",
  "pattern": "^fy_[0-9A-HJKMNP-TV-Z]{26}$"
}

200 · application/json

The fiscal year.

Required fields: id, label, startsOn, endsOn, status, createdAt

{
  "type": "object",
  "description": "Tenant fiscal year and its finalization state.",
  "required": [
    "id",
    "label",
    "startsOn",
    "endsOn",
    "status",
    "createdAt"
  ],
  "additionalProperties": false,
  "properties": {
    "id": {
      "type": "string",
      "description": "Opaque fiscal-year identifier.",
      "pattern": "^fy_[0-9A-HJKMNP-TV-Z]{26}$"
    },
    "label": {
      "type": "string"
    },
    "startsOn": {
      "type": "string",
      "format": "date"
    },
    "endsOn": {
      "type": "string",
      "format": "date"
    },
    "status": {
      "type": "string",
      "enum": [
        "open",
        "finalized"
      ],
      "x-enum-varnames": [
        "FiscalYearStatusOpen",
        "FiscalYearStatusFinalized"
      ],
      "description": "Finalized years cannot be changed."
    },
    "finalizedAt": {
      "type": [
        "string",
        "null"
      ],
      "format": "date-time"
    },
    "createdAt": {
      "type": "string",
      "format": "date-time"
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

yearId · path · required

Opaque fiscal-year identifier.

{
  "type": "string",
  "description": "Opaque fiscal-year identifier.",
  "pattern": "^fy_[0-9A-HJKMNP-TV-Z]{26}$"
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

application/json · required

Required fields: targetYearId, targetPeriodId, mappingRevisionId, resultAccountId, documentId, currency

{
  "type": "object",
  "description": "Consumer-selected target and evidence for one-currency opening.",
  "required": [
    "targetYearId",
    "targetPeriodId",
    "mappingRevisionId",
    "resultAccountId",
    "documentId",
    "currency"
  ],
  "additionalProperties": false,
  "properties": {
    "targetYearId": {
      "type": "string",
      "description": "Opaque fiscal-year identifier.",
      "pattern": "^fy_[0-9A-HJKMNP-TV-Z]{26}$"
    },
    "targetPeriodId": {
      "type": "string",
      "description": "Opaque period identifier.",
      "pattern": "^per_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "per_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "mappingRevisionId": {
      "description": "Opaque tenant-owned account mapping revision identifier.",
      "type": "string",
      "pattern": "^map_[0-9A-HJKMNP-TV-Z]{26}$"
    },
    "resultAccountId": {
      "type": "string",
      "description": "Opaque account identifier.",
      "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "documentId": {
      "type": "string",
      "description": "Opaque Beleg identifier. It does not encode storage identity.",
      "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "currency": {
      "type": "string",
      "pattern": "^[A-Z]{3}$"
    }
  }
}

200 · application/json

Posted opening entry or its existing representation.

Required fields: id, periodId, status, bookingDate, currency, lines, createdAt

{
  "type": "object",
  "description": "A Buchung — a draft, or a posted entry in the hash chain.",
  "required": [
    "id",
    "periodId",
    "status",
    "bookingDate",
    "currency",
    "lines",
    "createdAt"
  ],
  "additionalProperties": false,
  "properties": {
    "bookingText": {
      "type": [
        "string",
        "null"
      ],
      "minLength": 1,
      "maxLength": 500,
      "description": "Buchungstext, preserved exactly and immutable once posted. Null or omitted means absent; U+0000 is forbidden."
    },
    "externalReference": {
      "type": [
        "string",
        "null"
      ],
      "minLength": 1,
      "maxLength": 255,
      "description": "Caller business reference, preserved exactly and immutable once posted. Not unique; use Idempotency-Key for retries. Null or omitted means absent; U+0000 is forbidden."
    },
    "id": {
      "type": "string",
      "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
      "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "periodId": {
      "type": "string",
      "description": "Opaque period identifier.",
      "pattern": "^per_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "per_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "status": {
      "type": "string",
      "description": "`draft` is mutable and carries no `seq`; `posted` is in the hash chain and\nimmutable — corrections are new reversal entries (Storno).\n",
      "enum": [
        "draft",
        "posted"
      ]
    },
    "bookingDate": {
      "type": "string",
      "format": "date"
    },
    "currency": {
      "type": "string",
      "description": "ISO-4217 alphabetic currency code.",
      "pattern": "^[A-Z]{3}$",
      "examples": [
        "EUR"
      ]
    },
    "seq": {
      "type": [
        "integer",
        "null"
      ],
      "format": "int64",
      "description": "The legal Buchungsnummer — gapless and strictly increasing per tenant.\nAssigned at posting; null on a draft.\n"
    },
    "entryHash": {
      "type": [
        "string",
        "null"
      ],
      "description": "Opaque server-side audit fingerprint for this chain link. The canonical\npayload intentionally includes private identifiers that are not exposed\nby the public API, so clients must not treat this as a recomputable proof.\nAssigned at posting; null on a draft.\n",
      "pattern": "^[0-9a-f]{64}$"
    },
    "reversalOf": {
      "type": "string",
      "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
      "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "lines": {
      "type": "array",
      "minItems": 2,
      "items": {
        "type": "object",
        "description": "One line of a Buchung as booked.",
        "required": [
          "lineNo",
          "accountId",
          "accountNo",
          "side",
          "amount"
        ],
        "additionalProperties": false,
        "properties": {
          "taxRuleId": {
            "type": "string",
            "maxLength": 128,
            "description": "Optional immutable published rule; requires matching taxKey and effective booking date."
          },
          "lineNo": {
            "type": "integer",
            "description": "Position within the Buchung, starting at 1.",
            "minimum": 1
          },
          "accountId": {
            "type": "string",
            "description": "Opaque account identifier.",
            "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
            "examples": [
              "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
            ]
          },
          "accountNo": {
            "type": "string",
            "description": "The Kontonummer as booked — frozen at creation, so it keeps reading\ntrue even if the account is later renumbered (INVARIANT #10).\n"
          },
          "side": {
            "type": "string",
            "description": "Buchungsseite — Soll (debit) or Haben (credit).",
            "enum": [
              "debit",
              "credit"
            ]
          },
          "amount": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          },
          "taxKey": {
            "type": [
              "string",
              "null"
            ]
          }
        }
      }
    },
    "createdAt": {
      "type": "string",
      "format": "date-time"
    },
    "postedAt": {
      "type": [
        "string",
        "null"
      ],
      "format": "date-time"
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

yearId · path · required

Opaque fiscal-year identifier.

{
  "type": "string",
  "description": "Opaque fiscal-year identifier.",
  "pattern": "^fy_[0-9A-HJKMNP-TV-Z]{26}$"
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

application/json · required

Required fields: periodId, mappingRevisionId, resultAccountId, documentId

{
  "type": "object",
  "description": "Consumer-selected closing classification and evidence.",
  "required": [
    "periodId",
    "mappingRevisionId",
    "resultAccountId",
    "documentId"
  ],
  "additionalProperties": false,
  "properties": {
    "periodId": {
      "type": "string",
      "description": "Opaque period identifier.",
      "pattern": "^per_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "per_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "mappingRevisionId": {
      "description": "Opaque tenant-owned account mapping revision identifier.",
      "type": "string",
      "pattern": "^map_[0-9A-HJKMNP-TV-Z]{26}$"
    },
    "resultAccountId": {
      "type": "string",
      "description": "Opaque account identifier.",
      "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "documentId": {
      "type": "string",
      "description": "Opaque Beleg identifier. It does not encode storage identity.",
      "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    }
  }
}

200 · application/json

Posted closing entries and sealed period.

Required fields: entries, period

{
  "type": "object",
  "description": "Closing entries and the sealed period.",
  "required": [
    "entries",
    "period"
  ],
  "additionalProperties": false,
  "properties": {
    "entries": {
      "type": "array",
      "items": {
        "type": "object",
        "description": "A Buchung — a draft, or a posted entry in the hash chain.",
        "required": [
          "id",
          "periodId",
          "status",
          "bookingDate",
          "currency",
          "lines",
          "createdAt"
        ],
        "additionalProperties": false,
        "properties": {
          "bookingText": {
            "type": [
              "string",
              "null"
            ],
            "minLength": 1,
            "maxLength": 500,
            "description": "Buchungstext, preserved exactly and immutable once posted. Null or omitted means absent; U+0000 is forbidden."
          },
          "externalReference": {
            "type": [
              "string",
              "null"
            ],
            "minLength": 1,
            "maxLength": 255,
            "description": "Caller business reference, preserved exactly and immutable once posted. Not unique; use Idempotency-Key for retries. Null or omitted means absent; U+0000 is forbidden."
          },
          "id": {
            "type": "string",
            "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
            "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
            "examples": [
              "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
            ]
          },
          "periodId": {
            "type": "string",
            "description": "Opaque period identifier.",
            "pattern": "^per_[0-9A-HJKMNP-TV-Z]{26}$",
            "examples": [
              "per_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
            ]
          },
          "status": {
            "type": "string",
            "description": "`draft` is mutable and carries no `seq`; `posted` is in the hash chain and\nimmutable — corrections are new reversal entries (Storno).\n",
            "enum": [
              "draft",
              "posted"
            ]
          },
          "bookingDate": {
            "type": "string",
            "format": "date"
          },
          "currency": {
            "type": "string",
            "description": "ISO-4217 alphabetic currency code.",
            "pattern": "^[A-Z]{3}$",
            "examples": [
              "EUR"
            ]
          },
          "seq": {
            "type": [
              "integer",
              "null"
            ],
            "format": "int64",
            "description": "The legal Buchungsnummer — gapless and strictly increasing per tenant.\nAssigned at posting; null on a draft.\n"
          },
          "entryHash": {
            "type": [
              "string",
              "null"
            ],
            "description": "Opaque server-side audit fingerprint for this chain link. The canonical\npayload intentionally includes private identifiers that are not exposed\nby the public API, so clients must not treat this as a recomputable proof.\nAssigned at posting; null on a draft.\n",
            "pattern": "^[0-9a-f]{64}$"
          },
          "reversalOf": {
            "type": "string",
            "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
            "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
            "examples": [
              "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
            ]
          },
          "lines": {
            "type": "array",
            "minItems": 2,
            "items": {
              "type": "object",
              "description": "One line of a Buchung as booked.",
              "required": [
                "lineNo",
                "accountId",
                "accountNo",
                "side",
                "amount"
              ],
              "additionalProperties": false,
              "properties": {
                "taxRuleId": {
                  "type": "string",
                  "maxLength": 128,
                  "description": "Optional immutable published rule; requires matching taxKey and effective booking date."
                },
                "lineNo": {
                  "type": "integer",
                  "description": "Position within the Buchung, starting at 1.",
                  "minimum": 1
                },
                "accountId": {
                  "type": "string",
                  "description": "Opaque account identifier.",
                  "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
                  "examples": [
                    "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
                  ]
                },
                "accountNo": {
                  "type": "string",
                  "description": "The Kontonummer as booked — frozen at creation, so it keeps reading\ntrue even if the account is later renumbered (INVARIANT #10).\n"
                },
                "side": {
                  "type": "string",
                  "description": "Buchungsseite — Soll (debit) or Haben (credit).",
                  "enum": [
                    "debit",
                    "credit"
                  ]
                },
                "amount": {
                  "type": "object",
                  "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
                  "required": [
                    "amount",
                    "currency"
                  ],
                  "additionalProperties": false,
                  "properties": {
                    "amount": {
                      "type": "string",
                      "description": "Signed integer count of minor units, no separators, no exponent.",
                      "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                      "examples": [
                        "150000"
                      ]
                    },
                    "currency": {
                      "type": "string",
                      "description": "ISO-4217 alphabetic currency code.",
                      "pattern": "^[A-Z]{3}$",
                      "examples": [
                        "EUR"
                      ]
                    }
                  }
                },
                "taxKey": {
                  "type": [
                    "string",
                    "null"
                  ]
                }
              }
            }
          },
          "createdAt": {
            "type": "string",
            "format": "date-time"
          },
          "postedAt": {
            "type": [
              "string",
              "null"
            ],
            "format": "date-time"
          }
        }
      }
    },
    "period": {
      "type": "object",
      "description": "An accounting period and its Festschreibung state.",
      "required": [
        "id",
        "label",
        "startsOn",
        "endsOn",
        "status",
        "createdAt"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "type": "string",
          "description": "Opaque period identifier.",
          "pattern": "^per_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "per_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "label": {
          "type": "string",
          "examples": [
            "2026-01"
          ]
        },
        "startsOn": {
          "type": "string",
          "format": "date"
        },
        "endsOn": {
          "type": "string",
          "format": "date",
          "description": "Inclusive last day of the period."
        },
        "status": {
          "type": "string",
          "description": "`open` accepts postings; `festgeschrieben` is sealed and immutable\n(Festschreibung, §146 AO).\n",
          "enum": [
            "open",
            "festgeschrieben"
          ]
        },
        "festgeschriebenAt": {
          "type": [
            "string",
            "null"
          ],
          "format": "date-time",
          "description": "When the period was sealed; null while it is open."
        },
        "createdAt": {
          "type": "string",
          "format": "date-time"
        }
      }
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

yearId · path · required

Opaque fiscal-year identifier.

{
  "type": "string",
  "description": "Opaque fiscal-year identifier.",
  "pattern": "^fy_[0-9A-HJKMNP-TV-Z]{26}$"
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

200 · application/json

The finalized fiscal year.

Required fields: id, label, startsOn, endsOn, status, createdAt

{
  "type": "object",
  "description": "Tenant fiscal year and its finalization state.",
  "required": [
    "id",
    "label",
    "startsOn",
    "endsOn",
    "status",
    "createdAt"
  ],
  "additionalProperties": false,
  "properties": {
    "id": {
      "type": "string",
      "description": "Opaque fiscal-year identifier.",
      "pattern": "^fy_[0-9A-HJKMNP-TV-Z]{26}$"
    },
    "label": {
      "type": "string"
    },
    "startsOn": {
      "type": "string",
      "format": "date"
    },
    "endsOn": {
      "type": "string",
      "format": "date"
    },
    "status": {
      "type": "string",
      "enum": [
        "open",
        "finalized"
      ],
      "x-enum-varnames": [
        "FiscalYearStatusOpen",
        "FiscalYearStatusFinalized"
      ],
      "description": "Finalized years cannot be changed."
    },
    "finalizedAt": {
      "type": [
        "string",
        "null"
      ],
      "format": "date-time"
    },
    "createdAt": {
      "type": "string",
      "format": "date-time"
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

limit · query

Maximum number of items to return.

{
  "type": "integer",
  "minimum": 1,
  "maximum": 200,
  "default": 50
}

after · query

The nextCursor from the previous page.

{
  "type": "string",
  "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
  "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

status · query · required

Select drafts or posted entries.

{
  "type": "string",
  "description": "`draft` is mutable and carries no `seq`; `posted` is in the hash chain and\nimmutable — corrections are new reversal entries (Storno).\n",
  "enum": [
    "draft",
    "posted"
  ]
}

periodId · query

Restrict to this tenant's accounting period.

{
  "type": "string",
  "description": "Opaque period identifier.",
  "pattern": "^per_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "per_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

documentId · query

Only entries directly linked to this tenant's Beleg.

{
  "type": "string",
  "description": "Opaque Beleg identifier. It does not encode storage identity.",
  "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

bookingDateFrom · query

Inclusive earliest booking date.

{
  "type": "string",
  "format": "date"
}

bookingDateTo · query

Inclusive latest booking date; must not precede bookingDateFrom.

{
  "type": "string",
  "format": "date"
}

externalReference · query

Exact business reference; combines with all other filters. U+0000 is forbidden.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

200 · application/json

A page of journal entries with their lines.

Required fields: data

{
  "type": "object",
  "description": "One page in immutable entry-ID order; not a snapshot across requests.",
  "required": [
    "data"
  ],
  "additionalProperties": false,
  "properties": {
    "data": {
      "type": "array",
      "items": {
        "type": "object",
        "description": "A Buchung — a draft, or a posted entry in the hash chain.",
        "required": [
          "id",
          "periodId",
          "status",
          "bookingDate",
          "currency",
          "lines",
          "createdAt"
        ],
        "additionalProperties": false,
        "properties": {
          "bookingText": {
            "type": [
              "string",
              "null"
            ],
            "minLength": 1,
            "maxLength": 500,
            "description": "Buchungstext, preserved exactly and immutable once posted. Null or omitted means absent; U+0000 is forbidden."
          },
          "externalReference": {
            "type": [
              "string",
              "null"
            ],
            "minLength": 1,
            "maxLength": 255,
            "description": "Caller business reference, preserved exactly and immutable once posted. Not unique; use Idempotency-Key for retries. Null or omitted means absent; U+0000 is forbidden."
          },
          "id": {
            "type": "string",
            "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
            "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
            "examples": [
              "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
            ]
          },
          "periodId": {
            "type": "string",
            "description": "Opaque period identifier.",
            "pattern": "^per_[0-9A-HJKMNP-TV-Z]{26}$",
            "examples": [
              "per_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
            ]
          },
          "status": {
            "type": "string",
            "description": "`draft` is mutable and carries no `seq`; `posted` is in the hash chain and\nimmutable — corrections are new reversal entries (Storno).\n",
            "enum": [
              "draft",
              "posted"
            ]
          },
          "bookingDate": {
            "type": "string",
            "format": "date"
          },
          "currency": {
            "type": "string",
            "description": "ISO-4217 alphabetic currency code.",
            "pattern": "^[A-Z]{3}$",
            "examples": [
              "EUR"
            ]
          },
          "seq": {
            "type": [
              "integer",
              "null"
            ],
            "format": "int64",
            "description": "The legal Buchungsnummer — gapless and strictly increasing per tenant.\nAssigned at posting; null on a draft.\n"
          },
          "entryHash": {
            "type": [
              "string",
              "null"
            ],
            "description": "Opaque server-side audit fingerprint for this chain link. The canonical\npayload intentionally includes private identifiers that are not exposed\nby the public API, so clients must not treat this as a recomputable proof.\nAssigned at posting; null on a draft.\n",
            "pattern": "^[0-9a-f]{64}$"
          },
          "reversalOf": {
            "type": "string",
            "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
            "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
            "examples": [
              "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
            ]
          },
          "lines": {
            "type": "array",
            "minItems": 2,
            "items": {
              "type": "object",
              "description": "One line of a Buchung as booked.",
              "required": [
                "lineNo",
                "accountId",
                "accountNo",
                "side",
                "amount"
              ],
              "additionalProperties": false,
              "properties": {
                "taxRuleId": {
                  "type": "string",
                  "maxLength": 128,
                  "description": "Optional immutable published rule; requires matching taxKey and effective booking date."
                },
                "lineNo": {
                  "type": "integer",
                  "description": "Position within the Buchung, starting at 1.",
                  "minimum": 1
                },
                "accountId": {
                  "type": "string",
                  "description": "Opaque account identifier.",
                  "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
                  "examples": [
                    "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
                  ]
                },
                "accountNo": {
                  "type": "string",
                  "description": "The Kontonummer as booked — frozen at creation, so it keeps reading\ntrue even if the account is later renumbered (INVARIANT #10).\n"
                },
                "side": {
                  "type": "string",
                  "description": "Buchungsseite — Soll (debit) or Haben (credit).",
                  "enum": [
                    "debit",
                    "credit"
                  ]
                },
                "amount": {
                  "type": "object",
                  "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
                  "required": [
                    "amount",
                    "currency"
                  ],
                  "additionalProperties": false,
                  "properties": {
                    "amount": {
                      "type": "string",
                      "description": "Signed integer count of minor units, no separators, no exponent.",
                      "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                      "examples": [
                        "150000"
                      ]
                    },
                    "currency": {
                      "type": "string",
                      "description": "ISO-4217 alphabetic currency code.",
                      "pattern": "^[A-Z]{3}$",
                      "examples": [
                        "EUR"
                      ]
                    }
                  }
                },
                "taxKey": {
                  "type": [
                    "string",
                    "null"
                  ]
                }
              }
            }
          },
          "createdAt": {
            "type": "string",
            "format": "date-time"
          },
          "postedAt": {
            "type": [
              "string",
              "null"
            ],
            "format": "date-time"
          }
        }
      }
    },
    "nextCursor": {
      "type": "string",
      "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
      "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

403 · application/problem+json

The caller is authenticated for the tenant but lacks the explicit permission required for this operation. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

application/json · required

Required fields: periodId, bookingDate, currency, lines

{
  "type": "object",
  "description": "A balanced Buchung to draft.",
  "required": [
    "periodId",
    "bookingDate",
    "currency",
    "lines"
  ],
  "additionalProperties": false,
  "properties": {
    "bookingText": {
      "type": [
        "string",
        "null"
      ],
      "minLength": 1,
      "maxLength": 500,
      "description": "Buchungstext, preserved exactly and immutable once posted. Null or omitted means absent; U+0000 is forbidden."
    },
    "externalReference": {
      "type": [
        "string",
        "null"
      ],
      "minLength": 1,
      "maxLength": 255,
      "description": "Caller business reference, preserved exactly and immutable once posted. Not unique; use Idempotency-Key for retries. Null or omitted means absent; U+0000 is forbidden."
    },
    "periodId": {
      "type": "string",
      "description": "Opaque period identifier.",
      "pattern": "^per_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "per_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "bookingDate": {
      "type": "string",
      "format": "date",
      "description": "Buchungsdatum; must fall inside the period."
    },
    "currency": {
      "type": "string",
      "description": "ISO-4217 alphabetic currency code.",
      "pattern": "^[A-Z]{3}$",
      "examples": [
        "EUR"
      ]
    },
    "lines": {
      "type": "array",
      "description": "At least two lines. Every line's currency must equal the entry's, and\nthe debit total must equal the credit total.\n",
      "minItems": 2,
      "items": {
        "type": "object",
        "description": "One line of a Buchung to create — a Konto, a side, and an amount.",
        "required": [
          "accountId",
          "side",
          "amount"
        ],
        "additionalProperties": false,
        "properties": {
          "taxRuleId": {
            "type": "string",
            "maxLength": 128,
            "description": "Optional immutable published rule; requires matching taxKey and effective booking date."
          },
          "accountId": {
            "type": "string",
            "description": "Opaque account identifier.",
            "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
            "examples": [
              "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
            ]
          },
          "side": {
            "type": "string",
            "description": "Buchungsseite — Soll (debit) or Haben (credit).",
            "enum": [
              "debit",
              "credit"
            ]
          },
          "amount": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          },
          "taxKey": {
            "type": [
              "string",
              "null"
            ],
            "description": "Steuerschlüssel.",
            "maxLength": 32
          }
        }
      }
    }
  }
}

201 · application/json

The created draft.

Required fields: id, periodId, status, bookingDate, currency, lines, createdAt

{
  "type": "object",
  "description": "A Buchung — a draft, or a posted entry in the hash chain.",
  "required": [
    "id",
    "periodId",
    "status",
    "bookingDate",
    "currency",
    "lines",
    "createdAt"
  ],
  "additionalProperties": false,
  "properties": {
    "bookingText": {
      "type": [
        "string",
        "null"
      ],
      "minLength": 1,
      "maxLength": 500,
      "description": "Buchungstext, preserved exactly and immutable once posted. Null or omitted means absent; U+0000 is forbidden."
    },
    "externalReference": {
      "type": [
        "string",
        "null"
      ],
      "minLength": 1,
      "maxLength": 255,
      "description": "Caller business reference, preserved exactly and immutable once posted. Not unique; use Idempotency-Key for retries. Null or omitted means absent; U+0000 is forbidden."
    },
    "id": {
      "type": "string",
      "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
      "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "periodId": {
      "type": "string",
      "description": "Opaque period identifier.",
      "pattern": "^per_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "per_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "status": {
      "type": "string",
      "description": "`draft` is mutable and carries no `seq`; `posted` is in the hash chain and\nimmutable — corrections are new reversal entries (Storno).\n",
      "enum": [
        "draft",
        "posted"
      ]
    },
    "bookingDate": {
      "type": "string",
      "format": "date"
    },
    "currency": {
      "type": "string",
      "description": "ISO-4217 alphabetic currency code.",
      "pattern": "^[A-Z]{3}$",
      "examples": [
        "EUR"
      ]
    },
    "seq": {
      "type": [
        "integer",
        "null"
      ],
      "format": "int64",
      "description": "The legal Buchungsnummer — gapless and strictly increasing per tenant.\nAssigned at posting; null on a draft.\n"
    },
    "entryHash": {
      "type": [
        "string",
        "null"
      ],
      "description": "Opaque server-side audit fingerprint for this chain link. The canonical\npayload intentionally includes private identifiers that are not exposed\nby the public API, so clients must not treat this as a recomputable proof.\nAssigned at posting; null on a draft.\n",
      "pattern": "^[0-9a-f]{64}$"
    },
    "reversalOf": {
      "type": "string",
      "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
      "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "lines": {
      "type": "array",
      "minItems": 2,
      "items": {
        "type": "object",
        "description": "One line of a Buchung as booked.",
        "required": [
          "lineNo",
          "accountId",
          "accountNo",
          "side",
          "amount"
        ],
        "additionalProperties": false,
        "properties": {
          "taxRuleId": {
            "type": "string",
            "maxLength": 128,
            "description": "Optional immutable published rule; requires matching taxKey and effective booking date."
          },
          "lineNo": {
            "type": "integer",
            "description": "Position within the Buchung, starting at 1.",
            "minimum": 1
          },
          "accountId": {
            "type": "string",
            "description": "Opaque account identifier.",
            "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
            "examples": [
              "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
            ]
          },
          "accountNo": {
            "type": "string",
            "description": "The Kontonummer as booked — frozen at creation, so it keeps reading\ntrue even if the account is later renumbered (INVARIANT #10).\n"
          },
          "side": {
            "type": "string",
            "description": "Buchungsseite — Soll (debit) or Haben (credit).",
            "enum": [
              "debit",
              "credit"
            ]
          },
          "amount": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          },
          "taxKey": {
            "type": [
              "string",
              "null"
            ]
          }
        }
      }
    },
    "createdAt": {
      "type": "string",
      "format": "date-time"
    },
    "postedAt": {
      "type": [
        "string",
        "null"
      ],
      "format": "date-time"
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

entryId · path · required

Identifier of the Buchung.

{
  "type": "string",
  "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
  "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

If-Match · header · required

Exactly one strong item ETag observed from create, GET or replacement. Weak tags, wildcards and lists are rejected with 400. Missing tags return 428; stale tags return 412. Fetch again and retry with a fresh Idempotency-Key after a stale version.

{
  "type": "string",
  "pattern": "^\"je-v1-[A-Za-z0-9_-]{32}\"$"
}

204

The draft was discarded.

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

403 · application/problem+json

The caller is authenticated for the tenant but lacks the explicit permission required for this operation. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

412 · application/problem+json

The supplied `If-Match` validator is well-formed but stale. No resource state or audit evidence was changed. Fetch the item and retry the intended change with its new `ETag` and a fresh `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

428 · application/problem+json

This mutation requires the latest item `ETag` in `If-Match`; no resource state or audit evidence was changed.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

entryId · path · required

Identifier of the Buchung.

{
  "type": "string",
  "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
  "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

200 · application/json

The Buchung.

Required fields: id, periodId, status, bookingDate, currency, lines, createdAt

{
  "type": "object",
  "description": "A Buchung — a draft, or a posted entry in the hash chain.",
  "required": [
    "id",
    "periodId",
    "status",
    "bookingDate",
    "currency",
    "lines",
    "createdAt"
  ],
  "additionalProperties": false,
  "properties": {
    "bookingText": {
      "type": [
        "string",
        "null"
      ],
      "minLength": 1,
      "maxLength": 500,
      "description": "Buchungstext, preserved exactly and immutable once posted. Null or omitted means absent; U+0000 is forbidden."
    },
    "externalReference": {
      "type": [
        "string",
        "null"
      ],
      "minLength": 1,
      "maxLength": 255,
      "description": "Caller business reference, preserved exactly and immutable once posted. Not unique; use Idempotency-Key for retries. Null or omitted means absent; U+0000 is forbidden."
    },
    "id": {
      "type": "string",
      "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
      "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "periodId": {
      "type": "string",
      "description": "Opaque period identifier.",
      "pattern": "^per_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "per_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "status": {
      "type": "string",
      "description": "`draft` is mutable and carries no `seq`; `posted` is in the hash chain and\nimmutable — corrections are new reversal entries (Storno).\n",
      "enum": [
        "draft",
        "posted"
      ]
    },
    "bookingDate": {
      "type": "string",
      "format": "date"
    },
    "currency": {
      "type": "string",
      "description": "ISO-4217 alphabetic currency code.",
      "pattern": "^[A-Z]{3}$",
      "examples": [
        "EUR"
      ]
    },
    "seq": {
      "type": [
        "integer",
        "null"
      ],
      "format": "int64",
      "description": "The legal Buchungsnummer — gapless and strictly increasing per tenant.\nAssigned at posting; null on a draft.\n"
    },
    "entryHash": {
      "type": [
        "string",
        "null"
      ],
      "description": "Opaque server-side audit fingerprint for this chain link. The canonical\npayload intentionally includes private identifiers that are not exposed\nby the public API, so clients must not treat this as a recomputable proof.\nAssigned at posting; null on a draft.\n",
      "pattern": "^[0-9a-f]{64}$"
    },
    "reversalOf": {
      "type": "string",
      "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
      "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "lines": {
      "type": "array",
      "minItems": 2,
      "items": {
        "type": "object",
        "description": "One line of a Buchung as booked.",
        "required": [
          "lineNo",
          "accountId",
          "accountNo",
          "side",
          "amount"
        ],
        "additionalProperties": false,
        "properties": {
          "taxRuleId": {
            "type": "string",
            "maxLength": 128,
            "description": "Optional immutable published rule; requires matching taxKey and effective booking date."
          },
          "lineNo": {
            "type": "integer",
            "description": "Position within the Buchung, starting at 1.",
            "minimum": 1
          },
          "accountId": {
            "type": "string",
            "description": "Opaque account identifier.",
            "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
            "examples": [
              "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
            ]
          },
          "accountNo": {
            "type": "string",
            "description": "The Kontonummer as booked — frozen at creation, so it keeps reading\ntrue even if the account is later renumbered (INVARIANT #10).\n"
          },
          "side": {
            "type": "string",
            "description": "Buchungsseite — Soll (debit) or Haben (credit).",
            "enum": [
              "debit",
              "credit"
            ]
          },
          "amount": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          },
          "taxKey": {
            "type": [
              "string",
              "null"
            ]
          }
        }
      }
    },
    "createdAt": {
      "type": "string",
      "format": "date-time"
    },
    "postedAt": {
      "type": [
        "string",
        "null"
      ],
      "format": "date-time"
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

entryId · path · required

Identifier of the Buchung.

{
  "type": "string",
  "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
  "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

If-Match · header · required

Exactly one strong item ETag observed from create, GET or replacement. Weak tags, wildcards and lists are rejected with 400. Missing tags return 428; stale tags return 412. Fetch again and retry with a fresh Idempotency-Key after a stale version.

{
  "type": "string",
  "pattern": "^\"je-v1-[A-Za-z0-9_-]{32}\"$"
}

application/json · required

Required fields: periodId, bookingDate, currency, lines

{
  "type": "object",
  "description": "A balanced Buchung to draft.",
  "required": [
    "periodId",
    "bookingDate",
    "currency",
    "lines"
  ],
  "additionalProperties": false,
  "properties": {
    "bookingText": {
      "type": [
        "string",
        "null"
      ],
      "minLength": 1,
      "maxLength": 500,
      "description": "Buchungstext, preserved exactly and immutable once posted. Null or omitted means absent; U+0000 is forbidden."
    },
    "externalReference": {
      "type": [
        "string",
        "null"
      ],
      "minLength": 1,
      "maxLength": 255,
      "description": "Caller business reference, preserved exactly and immutable once posted. Not unique; use Idempotency-Key for retries. Null or omitted means absent; U+0000 is forbidden."
    },
    "periodId": {
      "type": "string",
      "description": "Opaque period identifier.",
      "pattern": "^per_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "per_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "bookingDate": {
      "type": "string",
      "format": "date",
      "description": "Buchungsdatum; must fall inside the period."
    },
    "currency": {
      "type": "string",
      "description": "ISO-4217 alphabetic currency code.",
      "pattern": "^[A-Z]{3}$",
      "examples": [
        "EUR"
      ]
    },
    "lines": {
      "type": "array",
      "description": "At least two lines. Every line's currency must equal the entry's, and\nthe debit total must equal the credit total.\n",
      "minItems": 2,
      "items": {
        "type": "object",
        "description": "One line of a Buchung to create — a Konto, a side, and an amount.",
        "required": [
          "accountId",
          "side",
          "amount"
        ],
        "additionalProperties": false,
        "properties": {
          "taxRuleId": {
            "type": "string",
            "maxLength": 128,
            "description": "Optional immutable published rule; requires matching taxKey and effective booking date."
          },
          "accountId": {
            "type": "string",
            "description": "Opaque account identifier.",
            "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
            "examples": [
              "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
            ]
          },
          "side": {
            "type": "string",
            "description": "Buchungsseite — Soll (debit) or Haben (credit).",
            "enum": [
              "debit",
              "credit"
            ]
          },
          "amount": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          },
          "taxKey": {
            "type": [
              "string",
              "null"
            ],
            "description": "Steuerschlüssel.",
            "maxLength": 32
          }
        }
      }
    }
  }
}

200 · application/json

The replaced draft.

Required fields: id, periodId, status, bookingDate, currency, lines, createdAt

{
  "type": "object",
  "description": "A Buchung — a draft, or a posted entry in the hash chain.",
  "required": [
    "id",
    "periodId",
    "status",
    "bookingDate",
    "currency",
    "lines",
    "createdAt"
  ],
  "additionalProperties": false,
  "properties": {
    "bookingText": {
      "type": [
        "string",
        "null"
      ],
      "minLength": 1,
      "maxLength": 500,
      "description": "Buchungstext, preserved exactly and immutable once posted. Null or omitted means absent; U+0000 is forbidden."
    },
    "externalReference": {
      "type": [
        "string",
        "null"
      ],
      "minLength": 1,
      "maxLength": 255,
      "description": "Caller business reference, preserved exactly and immutable once posted. Not unique; use Idempotency-Key for retries. Null or omitted means absent; U+0000 is forbidden."
    },
    "id": {
      "type": "string",
      "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
      "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "periodId": {
      "type": "string",
      "description": "Opaque period identifier.",
      "pattern": "^per_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "per_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "status": {
      "type": "string",
      "description": "`draft` is mutable and carries no `seq`; `posted` is in the hash chain and\nimmutable — corrections are new reversal entries (Storno).\n",
      "enum": [
        "draft",
        "posted"
      ]
    },
    "bookingDate": {
      "type": "string",
      "format": "date"
    },
    "currency": {
      "type": "string",
      "description": "ISO-4217 alphabetic currency code.",
      "pattern": "^[A-Z]{3}$",
      "examples": [
        "EUR"
      ]
    },
    "seq": {
      "type": [
        "integer",
        "null"
      ],
      "format": "int64",
      "description": "The legal Buchungsnummer — gapless and strictly increasing per tenant.\nAssigned at posting; null on a draft.\n"
    },
    "entryHash": {
      "type": [
        "string",
        "null"
      ],
      "description": "Opaque server-side audit fingerprint for this chain link. The canonical\npayload intentionally includes private identifiers that are not exposed\nby the public API, so clients must not treat this as a recomputable proof.\nAssigned at posting; null on a draft.\n",
      "pattern": "^[0-9a-f]{64}$"
    },
    "reversalOf": {
      "type": "string",
      "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
      "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "lines": {
      "type": "array",
      "minItems": 2,
      "items": {
        "type": "object",
        "description": "One line of a Buchung as booked.",
        "required": [
          "lineNo",
          "accountId",
          "accountNo",
          "side",
          "amount"
        ],
        "additionalProperties": false,
        "properties": {
          "taxRuleId": {
            "type": "string",
            "maxLength": 128,
            "description": "Optional immutable published rule; requires matching taxKey and effective booking date."
          },
          "lineNo": {
            "type": "integer",
            "description": "Position within the Buchung, starting at 1.",
            "minimum": 1
          },
          "accountId": {
            "type": "string",
            "description": "Opaque account identifier.",
            "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
            "examples": [
              "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
            ]
          },
          "accountNo": {
            "type": "string",
            "description": "The Kontonummer as booked — frozen at creation, so it keeps reading\ntrue even if the account is later renumbered (INVARIANT #10).\n"
          },
          "side": {
            "type": "string",
            "description": "Buchungsseite — Soll (debit) or Haben (credit).",
            "enum": [
              "debit",
              "credit"
            ]
          },
          "amount": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          },
          "taxKey": {
            "type": [
              "string",
              "null"
            ]
          }
        }
      }
    },
    "createdAt": {
      "type": "string",
      "format": "date-time"
    },
    "postedAt": {
      "type": [
        "string",
        "null"
      ],
      "format": "date-time"
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

403 · application/problem+json

The caller is authenticated for the tenant but lacks the explicit permission required for this operation. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

412 · application/problem+json

The supplied `If-Match` validator is well-formed but stale. No resource state or audit evidence was changed. Fetch the item and retry the intended change with its new `ETag` and a fresh `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

428 · application/problem+json

This mutation requires the latest item `ETag` in `If-Match`; no resource state or audit evidence was changed.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

entryId · path · required

Identifier of the Buchung.

{
  "type": "string",
  "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
  "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

documentId · path · required

Identifier of the Beleg.

{
  "type": "string",
  "description": "Opaque Beleg identifier. It does not encode storage identity.",
  "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

204

The document is linked. Repeating the link is a no-op.

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

entryId · path · required

Identifier of the Buchung.

{
  "type": "string",
  "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
  "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

If-Match · header

Optional strong item ETag of the reviewed draft. Checked under the same lock as posting. A stale revision returns 412; omission preserves the existing unconditional posting behavior. Weak tags, wildcards, duplicate values and lists return 400. A failed request rolls back its key and can reuse it after reviewing the current draft. Use a new Idempotency-Key for a new intent after a previously successful request.

{
  "type": "string",
  "pattern": "^\"je-v1-[A-Za-z0-9_-]{32}\"$"
}

200 · application/json

The posted Buchung.

Required fields: id, periodId, status, bookingDate, currency, lines, createdAt

{
  "type": "object",
  "description": "A Buchung — a draft, or a posted entry in the hash chain.",
  "required": [
    "id",
    "periodId",
    "status",
    "bookingDate",
    "currency",
    "lines",
    "createdAt"
  ],
  "additionalProperties": false,
  "properties": {
    "bookingText": {
      "type": [
        "string",
        "null"
      ],
      "minLength": 1,
      "maxLength": 500,
      "description": "Buchungstext, preserved exactly and immutable once posted. Null or omitted means absent; U+0000 is forbidden."
    },
    "externalReference": {
      "type": [
        "string",
        "null"
      ],
      "minLength": 1,
      "maxLength": 255,
      "description": "Caller business reference, preserved exactly and immutable once posted. Not unique; use Idempotency-Key for retries. Null or omitted means absent; U+0000 is forbidden."
    },
    "id": {
      "type": "string",
      "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
      "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "periodId": {
      "type": "string",
      "description": "Opaque period identifier.",
      "pattern": "^per_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "per_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "status": {
      "type": "string",
      "description": "`draft` is mutable and carries no `seq`; `posted` is in the hash chain and\nimmutable — corrections are new reversal entries (Storno).\n",
      "enum": [
        "draft",
        "posted"
      ]
    },
    "bookingDate": {
      "type": "string",
      "format": "date"
    },
    "currency": {
      "type": "string",
      "description": "ISO-4217 alphabetic currency code.",
      "pattern": "^[A-Z]{3}$",
      "examples": [
        "EUR"
      ]
    },
    "seq": {
      "type": [
        "integer",
        "null"
      ],
      "format": "int64",
      "description": "The legal Buchungsnummer — gapless and strictly increasing per tenant.\nAssigned at posting; null on a draft.\n"
    },
    "entryHash": {
      "type": [
        "string",
        "null"
      ],
      "description": "Opaque server-side audit fingerprint for this chain link. The canonical\npayload intentionally includes private identifiers that are not exposed\nby the public API, so clients must not treat this as a recomputable proof.\nAssigned at posting; null on a draft.\n",
      "pattern": "^[0-9a-f]{64}$"
    },
    "reversalOf": {
      "type": "string",
      "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
      "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "lines": {
      "type": "array",
      "minItems": 2,
      "items": {
        "type": "object",
        "description": "One line of a Buchung as booked.",
        "required": [
          "lineNo",
          "accountId",
          "accountNo",
          "side",
          "amount"
        ],
        "additionalProperties": false,
        "properties": {
          "taxRuleId": {
            "type": "string",
            "maxLength": 128,
            "description": "Optional immutable published rule; requires matching taxKey and effective booking date."
          },
          "lineNo": {
            "type": "integer",
            "description": "Position within the Buchung, starting at 1.",
            "minimum": 1
          },
          "accountId": {
            "type": "string",
            "description": "Opaque account identifier.",
            "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
            "examples": [
              "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
            ]
          },
          "accountNo": {
            "type": "string",
            "description": "The Kontonummer as booked — frozen at creation, so it keeps reading\ntrue even if the account is later renumbered (INVARIANT #10).\n"
          },
          "side": {
            "type": "string",
            "description": "Buchungsseite — Soll (debit) or Haben (credit).",
            "enum": [
              "debit",
              "credit"
            ]
          },
          "amount": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          },
          "taxKey": {
            "type": [
              "string",
              "null"
            ]
          }
        }
      }
    },
    "createdAt": {
      "type": "string",
      "format": "date-time"
    },
    "postedAt": {
      "type": [
        "string",
        "null"
      ],
      "format": "date-time"
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

412 · application/problem+json

The supplied `If-Match` validator is well-formed but stale. No resource state or audit evidence was changed. Fetch the item and retry the intended change with its new `ETag` and a fresh `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

entryId · path · required

Identifier of the Buchung.

{
  "type": "string",
  "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
  "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

application/json · required

Required fields: periodId, bookingDate

{
  "type": "object",
  "description": "Posting coordinates for a new Storno; economic data, bookingText and externalReference are inherited unchanged from the original.",
  "required": [
    "periodId",
    "bookingDate"
  ],
  "additionalProperties": false,
  "properties": {
    "periodId": {
      "type": "string",
      "description": "Opaque period identifier.",
      "pattern": "^per_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "per_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "bookingDate": {
      "type": "string",
      "format": "date",
      "description": "Buchungsdatum; must fall inside the destination period."
    }
  }
}

201 · application/json

The newly created and posted Storno.

Required fields: id, periodId, status, bookingDate, currency, lines, createdAt

{
  "type": "object",
  "description": "A Buchung — a draft, or a posted entry in the hash chain.",
  "required": [
    "id",
    "periodId",
    "status",
    "bookingDate",
    "currency",
    "lines",
    "createdAt"
  ],
  "additionalProperties": false,
  "properties": {
    "bookingText": {
      "type": [
        "string",
        "null"
      ],
      "minLength": 1,
      "maxLength": 500,
      "description": "Buchungstext, preserved exactly and immutable once posted. Null or omitted means absent; U+0000 is forbidden."
    },
    "externalReference": {
      "type": [
        "string",
        "null"
      ],
      "minLength": 1,
      "maxLength": 255,
      "description": "Caller business reference, preserved exactly and immutable once posted. Not unique; use Idempotency-Key for retries. Null or omitted means absent; U+0000 is forbidden."
    },
    "id": {
      "type": "string",
      "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
      "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "periodId": {
      "type": "string",
      "description": "Opaque period identifier.",
      "pattern": "^per_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "per_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "status": {
      "type": "string",
      "description": "`draft` is mutable and carries no `seq`; `posted` is in the hash chain and\nimmutable — corrections are new reversal entries (Storno).\n",
      "enum": [
        "draft",
        "posted"
      ]
    },
    "bookingDate": {
      "type": "string",
      "format": "date"
    },
    "currency": {
      "type": "string",
      "description": "ISO-4217 alphabetic currency code.",
      "pattern": "^[A-Z]{3}$",
      "examples": [
        "EUR"
      ]
    },
    "seq": {
      "type": [
        "integer",
        "null"
      ],
      "format": "int64",
      "description": "The legal Buchungsnummer — gapless and strictly increasing per tenant.\nAssigned at posting; null on a draft.\n"
    },
    "entryHash": {
      "type": [
        "string",
        "null"
      ],
      "description": "Opaque server-side audit fingerprint for this chain link. The canonical\npayload intentionally includes private identifiers that are not exposed\nby the public API, so clients must not treat this as a recomputable proof.\nAssigned at posting; null on a draft.\n",
      "pattern": "^[0-9a-f]{64}$"
    },
    "reversalOf": {
      "type": "string",
      "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
      "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "lines": {
      "type": "array",
      "minItems": 2,
      "items": {
        "type": "object",
        "description": "One line of a Buchung as booked.",
        "required": [
          "lineNo",
          "accountId",
          "accountNo",
          "side",
          "amount"
        ],
        "additionalProperties": false,
        "properties": {
          "taxRuleId": {
            "type": "string",
            "maxLength": 128,
            "description": "Optional immutable published rule; requires matching taxKey and effective booking date."
          },
          "lineNo": {
            "type": "integer",
            "description": "Position within the Buchung, starting at 1.",
            "minimum": 1
          },
          "accountId": {
            "type": "string",
            "description": "Opaque account identifier.",
            "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
            "examples": [
              "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
            ]
          },
          "accountNo": {
            "type": "string",
            "description": "The Kontonummer as booked — frozen at creation, so it keeps reading\ntrue even if the account is later renumbered (INVARIANT #10).\n"
          },
          "side": {
            "type": "string",
            "description": "Buchungsseite — Soll (debit) or Haben (credit).",
            "enum": [
              "debit",
              "credit"
            ]
          },
          "amount": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          },
          "taxKey": {
            "type": [
              "string",
              "null"
            ]
          }
        }
      }
    },
    "createdAt": {
      "type": "string",
      "format": "date-time"
    },
    "postedAt": {
      "type": [
        "string",
        "null"
      ],
      "format": "date-time"
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

limit · query

Maximum number of items to return.

{
  "type": "integer",
  "minimum": 1,
  "maximum": 200,
  "default": 50
}

after · query

Return items after this period — the `nextCursor` of the previous page.

{
  "type": "string",
  "description": "Opaque period identifier.",
  "pattern": "^per_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "per_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

200 · application/json

A page of periods.

Required fields: data

{
  "type": "object",
  "description": "One page of periods, earliest start date first.",
  "required": [
    "data"
  ],
  "additionalProperties": false,
  "properties": {
    "data": {
      "type": "array",
      "items": {
        "type": "object",
        "description": "An accounting period and its Festschreibung state.",
        "required": [
          "id",
          "label",
          "startsOn",
          "endsOn",
          "status",
          "createdAt"
        ],
        "additionalProperties": false,
        "properties": {
          "id": {
            "type": "string",
            "description": "Opaque period identifier.",
            "pattern": "^per_[0-9A-HJKMNP-TV-Z]{26}$",
            "examples": [
              "per_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
            ]
          },
          "label": {
            "type": "string",
            "examples": [
              "2026-01"
            ]
          },
          "startsOn": {
            "type": "string",
            "format": "date"
          },
          "endsOn": {
            "type": "string",
            "format": "date",
            "description": "Inclusive last day of the period."
          },
          "status": {
            "type": "string",
            "description": "`open` accepts postings; `festgeschrieben` is sealed and immutable\n(Festschreibung, §146 AO).\n",
            "enum": [
              "open",
              "festgeschrieben"
            ]
          },
          "festgeschriebenAt": {
            "type": [
              "string",
              "null"
            ],
            "format": "date-time",
            "description": "When the period was sealed; null while it is open."
          },
          "createdAt": {
            "type": "string",
            "format": "date-time"
          }
        }
      }
    },
    "nextCursor": {
      "type": "string",
      "description": "Opaque period identifier.",
      "pattern": "^per_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "per_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

application/json · required

Required fields: label, startsOn, endsOn

{
  "type": "object",
  "description": "Fields accepted when opening a period.",
  "required": [
    "label",
    "startsOn",
    "endsOn"
  ],
  "additionalProperties": false,
  "properties": {
    "label": {
      "type": "string",
      "minLength": 1,
      "maxLength": 64,
      "examples": [
        "2026-01"
      ]
    },
    "startsOn": {
      "type": "string",
      "format": "date"
    },
    "endsOn": {
      "type": "string",
      "format": "date",
      "description": "Inclusive last day; must not precede `startsOn`."
    }
  }
}

201 · application/json

The created period.

Required fields: id, label, startsOn, endsOn, status, createdAt

{
  "type": "object",
  "description": "An accounting period and its Festschreibung state.",
  "required": [
    "id",
    "label",
    "startsOn",
    "endsOn",
    "status",
    "createdAt"
  ],
  "additionalProperties": false,
  "properties": {
    "id": {
      "type": "string",
      "description": "Opaque period identifier.",
      "pattern": "^per_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "per_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "label": {
      "type": "string",
      "examples": [
        "2026-01"
      ]
    },
    "startsOn": {
      "type": "string",
      "format": "date"
    },
    "endsOn": {
      "type": "string",
      "format": "date",
      "description": "Inclusive last day of the period."
    },
    "status": {
      "type": "string",
      "description": "`open` accepts postings; `festgeschrieben` is sealed and immutable\n(Festschreibung, §146 AO).\n",
      "enum": [
        "open",
        "festgeschrieben"
      ]
    },
    "festgeschriebenAt": {
      "type": [
        "string",
        "null"
      ],
      "format": "date-time",
      "description": "When the period was sealed; null while it is open."
    },
    "createdAt": {
      "type": "string",
      "format": "date-time"
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

periodId · path · required

Identifier of the accounting period.

{
  "type": "string",
  "description": "Opaque period identifier.",
  "pattern": "^per_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "per_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

200 · application/json

The period.

Required fields: id, label, startsOn, endsOn, status, createdAt

{
  "type": "object",
  "description": "An accounting period and its Festschreibung state.",
  "required": [
    "id",
    "label",
    "startsOn",
    "endsOn",
    "status",
    "createdAt"
  ],
  "additionalProperties": false,
  "properties": {
    "id": {
      "type": "string",
      "description": "Opaque period identifier.",
      "pattern": "^per_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "per_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "label": {
      "type": "string",
      "examples": [
        "2026-01"
      ]
    },
    "startsOn": {
      "type": "string",
      "format": "date"
    },
    "endsOn": {
      "type": "string",
      "format": "date",
      "description": "Inclusive last day of the period."
    },
    "status": {
      "type": "string",
      "description": "`open` accepts postings; `festgeschrieben` is sealed and immutable\n(Festschreibung, §146 AO).\n",
      "enum": [
        "open",
        "festgeschrieben"
      ]
    },
    "festgeschriebenAt": {
      "type": [
        "string",
        "null"
      ],
      "format": "date-time",
      "description": "When the period was sealed; null while it is open."
    },
    "createdAt": {
      "type": "string",
      "format": "date-time"
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

periodId · path · required

Identifier of the accounting period.

{
  "type": "string",
  "description": "Opaque period identifier.",
  "pattern": "^per_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "per_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

200 · application/json

The sealed period, or its unchanged terminal representation.

Required fields: id, label, startsOn, endsOn, status, createdAt

{
  "type": "object",
  "description": "An accounting period and its Festschreibung state.",
  "required": [
    "id",
    "label",
    "startsOn",
    "endsOn",
    "status",
    "createdAt"
  ],
  "additionalProperties": false,
  "properties": {
    "id": {
      "type": "string",
      "description": "Opaque period identifier.",
      "pattern": "^per_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "per_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "label": {
      "type": "string",
      "examples": [
        "2026-01"
      ]
    },
    "startsOn": {
      "type": "string",
      "format": "date"
    },
    "endsOn": {
      "type": "string",
      "format": "date",
      "description": "Inclusive last day of the period."
    },
    "status": {
      "type": "string",
      "description": "`open` accepts postings; `festgeschrieben` is sealed and immutable\n(Festschreibung, §146 AO).\n",
      "enum": [
        "open",
        "festgeschrieben"
      ]
    },
    "festgeschriebenAt": {
      "type": [
        "string",
        "null"
      ],
      "format": "date-time",
      "description": "When the period was sealed; null while it is open."
    },
    "createdAt": {
      "type": "string",
      "format": "date-time"
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

fiscalYearId · query · required

Fiscal year whose inclusive dates delimit posted activity.

{
  "type": "string",
  "description": "Opaque fiscal-year identifier.",
  "pattern": "^fy_[0-9A-HJKMNP-TV-Z]{26}$"
}

mappingRevisionId · query · required

Immutable consumer-owned account classification.

{
  "description": "Opaque tenant-owned account mapping revision identifier.",
  "type": "string",
  "pattern": "^map_[0-9A-HJKMNP-TV-Z]{26}$"
}

asOf · query

Inclusive posted-entry cutoff; omit for latest, or reuse a prior response's asOf.

{
  "type": "string",
  "description": "A posted tenant entry's public ID, or empty for the permanent zero cutoff.",
  "pattern": "^(empty|je_[0-9A-HJKMNP-TV-Z]{26})$",
  "examples": [
    "empty"
  ]
}

currency · query

Restrict to one currency without conversion; omit to include each separately.

{
  "type": "string",
  "description": "ISO-4217 alphabetic currency code.",
  "pattern": "^[A-Z]{3}$",
  "examples": [
    "EUR"
  ]
}

200 · application/json

Bilanz and GuV sections with account drilldowns and currency totals.

Required fields: asOf, fiscalYearId, mappingRevisionId, mappingDigest, bookingDateFrom, bookingDateTo, closingEntryIds, data, totals

{
  "type": "object",
  "description": "Reproducible year-scoped reports under an explicit immutable mapping.",
  "required": [
    "asOf",
    "fiscalYearId",
    "mappingRevisionId",
    "mappingDigest",
    "bookingDateFrom",
    "bookingDateTo",
    "closingEntryIds",
    "data",
    "totals"
  ],
  "additionalProperties": false,
  "properties": {
    "asOf": {
      "type": "string",
      "description": "A posted tenant entry's public ID, or empty for the permanent zero cutoff.",
      "pattern": "^(empty|je_[0-9A-HJKMNP-TV-Z]{26})$",
      "examples": [
        "empty"
      ]
    },
    "fiscalYearId": {
      "type": "string",
      "description": "Opaque fiscal-year identifier.",
      "pattern": "^fy_[0-9A-HJKMNP-TV-Z]{26}$"
    },
    "mappingRevisionId": {
      "description": "Opaque tenant-owned account mapping revision identifier.",
      "type": "string",
      "pattern": "^map_[0-9A-HJKMNP-TV-Z]{26}$"
    },
    "mappingDigest": {
      "type": "string",
      "pattern": "^sha256:[0-9a-f]{64}$"
    },
    "bookingDateFrom": {
      "type": "string",
      "format": "date"
    },
    "bookingDateTo": {
      "type": "string",
      "format": "date"
    },
    "closingEntryIds": {
      "type": "array",
      "items": {
        "type": "string",
        "description": "Opaque Buchung identifier. Not the Buchungsnummer — that is `seq`.",
        "pattern": "^je_[0-9A-HJKMNP-TV-Z]{26}$",
        "examples": [
          "je_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
        ]
      }
    },
    "data": {
      "type": "array",
      "items": {
        "type": "object",
        "description": "One consumer-defined report section and its underlying accounts.",
        "required": [
          "classification",
          "reportCode",
          "reportName",
          "amount",
          "accounts"
        ],
        "additionalProperties": false,
        "properties": {
          "classification": {
            "description": "Explicit consumer classification for financial reporting.",
            "type": "string",
            "enum": [
              "asset",
              "liability",
              "equity",
              "income",
              "expense"
            ]
          },
          "reportCode": {
            "type": "string"
          },
          "reportName": {
            "type": "string"
          },
          "amount": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          },
          "accounts": {
            "type": "array",
            "items": {
              "type": "object",
              "description": "One account's year-scoped net in its classification's sign convention.",
              "required": [
                "accountId",
                "accountNo",
                "accountName",
                "amount"
              ],
              "additionalProperties": false,
              "properties": {
                "accountId": {
                  "type": "string",
                  "description": "Opaque account identifier.",
                  "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
                  "examples": [
                    "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
                  ]
                },
                "accountNo": {
                  "type": "string"
                },
                "accountName": {
                  "type": "string"
                },
                "amount": {
                  "type": "object",
                  "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
                  "required": [
                    "amount",
                    "currency"
                  ],
                  "additionalProperties": false,
                  "properties": {
                    "amount": {
                      "type": "string",
                      "description": "Signed integer count of minor units, no separators, no exponent.",
                      "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                      "examples": [
                        "150000"
                      ]
                    },
                    "currency": {
                      "type": "string",
                      "description": "ISO-4217 alphabetic currency code.",
                      "pattern": "^[A-Z]{3}$",
                      "examples": [
                        "EUR"
                      ]
                    }
                  }
                }
              }
            }
          }
        }
      }
    },
    "totals": {
      "type": "array",
      "items": {
        "type": "object",
        "description": "Separate balance sheet and profit/loss control totals in one currency.",
        "required": [
          "currency",
          "assets",
          "liabilities",
          "equity",
          "income",
          "expense",
          "result",
          "balanceDifference"
        ],
        "additionalProperties": false,
        "properties": {
          "currency": {
            "type": "string",
            "description": "ISO-4217 alphabetic currency code.",
            "pattern": "^[A-Z]{3}$",
            "examples": [
              "EUR"
            ]
          },
          "assets": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          },
          "liabilities": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          },
          "equity": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          },
          "income": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          },
          "expense": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          },
          "result": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          },
          "balanceDifference": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          }
        }
      }
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

403 · application/problem+json

The caller is authenticated for the tenant but lacks the explicit permission required for this operation. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

asOf · query

Inclusive posted-entry cutoff; omit for latest, or reuse a prior response's asOf.

{
  "type": "string",
  "description": "A posted tenant entry's public ID, or empty for the permanent zero cutoff.",
  "pattern": "^(empty|je_[0-9A-HJKMNP-TV-Z]{26})$",
  "examples": [
    "empty"
  ]
}

currency · query

Restrict to one currency without conversion; omit to include each separately.

{
  "type": "string",
  "description": "ISO-4217 alphabetic currency code.",
  "pattern": "^[A-Z]{3}$",
  "examples": [
    "EUR"
  ]
}

bookingDateFrom · query

Inclusive earliest booking date for movements; earlier history forms openingBalance.

{
  "type": "string",
  "format": "date"
}

bookingDateTo · query

Inclusive latest booking date; must not precede bookingDateFrom.

{
  "type": "string",
  "format": "date"
}

200 · application/json

Complete account rows and per-currency control totals.

Required fields: asOf, data, totals

{
  "type": "object",
  "description": "Summen- und Saldenliste with exact currency control totals.",
  "required": [
    "asOf",
    "data",
    "totals"
  ],
  "additionalProperties": false,
  "properties": {
    "asOf": {
      "type": "string",
      "description": "A posted tenant entry's public ID, or empty for the permanent zero cutoff.",
      "pattern": "^(empty|je_[0-9A-HJKMNP-TV-Z]{26})$",
      "examples": [
        "empty"
      ]
    },
    "data": {
      "type": "array",
      "items": {
        "type": "object",
        "description": "Exact totals for one account and currency.",
        "required": [
          "accountId",
          "accountNo",
          "currency",
          "openingBalance",
          "debitTotal",
          "creditTotal",
          "closingBalance"
        ],
        "additionalProperties": false,
        "properties": {
          "accountId": {
            "type": "string",
            "description": "Opaque account identifier.",
            "pattern": "^acct_[0-9A-HJKMNP-TV-Z]{26}$",
            "examples": [
              "acct_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
            ]
          },
          "accountNo": {
            "type": "string",
            "description": "Account number from the latest participating posted line."
          },
          "currency": {
            "type": "string",
            "description": "ISO-4217 alphabetic currency code.",
            "pattern": "^[A-Z]{3}$",
            "examples": [
              "EUR"
            ]
          },
          "openingBalance": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          },
          "debitTotal": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          },
          "creditTotal": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          },
          "closingBalance": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          }
        }
      }
    },
    "totals": {
      "type": "array",
      "items": {
        "type": "object",
        "description": "Exact debit/credit totals and signed balances in one currency.",
        "required": [
          "currency",
          "openingBalance",
          "debitTotal",
          "creditTotal",
          "closingBalance"
        ],
        "additionalProperties": false,
        "properties": {
          "currency": {
            "type": "string",
            "description": "ISO-4217 alphabetic currency code.",
            "pattern": "^[A-Z]{3}$",
            "examples": [
              "EUR"
            ]
          },
          "openingBalance": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          },
          "debitTotal": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          },
          "creditTotal": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          },
          "closingBalance": {
            "type": "object",
            "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
            "required": [
              "amount",
              "currency"
            ],
            "additionalProperties": false,
            "properties": {
              "amount": {
                "type": "string",
                "description": "Signed integer count of minor units, no separators, no exponent.",
                "pattern": "^-?(0|[1-9][0-9]{0,18})$",
                "examples": [
                  "150000"
                ]
              },
              "currency": {
                "type": "string",
                "description": "ISO-4217 alphabetic currency code.",
                "pattern": "^[A-Z]{3}$",
                "examples": [
                  "EUR"
                ]
              }
            }
          }
        }
      }
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

403 · application/problem+json

The caller is authenticated for the tenant but lacks the explicit permission required for this operation. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

application/json · required

Required fields: taxRuleId, bookingDate, net

{
  "description": "Explicit net amount, booking date and qualified rule.",
  "type": "object",
  "additionalProperties": false,
  "required": [
    "taxRuleId",
    "bookingDate",
    "net"
  ],
  "properties": {
    "taxRuleId": {
      "type": "string",
      "maxLength": 128
    },
    "bookingDate": {
      "type": "string",
      "format": "date"
    },
    "net": {
      "type": "object",
      "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
      "required": [
        "amount",
        "currency"
      ],
      "additionalProperties": false,
      "properties": {
        "amount": {
          "type": "string",
          "description": "Signed integer count of minor units, no separators, no exponent.",
          "pattern": "^-?(0|[1-9][0-9]{0,18})$",
          "examples": [
            "150000"
          ]
        },
        "currency": {
          "type": "string",
          "description": "ISO-4217 alphabetic currency code.",
          "pattern": "^[A-Z]{3}$",
          "examples": [
            "EUR"
          ]
        }
      }
    }
  }
}

200 · application/json

Exact calculation and immutable rule evidence.

Required fields: tax, evidence

{
  "description": "Exact rounded tax with the selected rule provenance.",
  "type": "object",
  "additionalProperties": false,
  "required": [
    "tax",
    "evidence"
  ],
  "properties": {
    "tax": {
      "type": "object",
      "description": "An exact monetary amount. `amount` is an integer string in the currency's\nMINOR units (cents for EUR) — never a JSON number, so it cannot be rounded\nthrough a binary float. `\"150000\"` with currency `EUR` is 1500,00 €.\n",
      "required": [
        "amount",
        "currency"
      ],
      "additionalProperties": false,
      "properties": {
        "amount": {
          "type": "string",
          "description": "Signed integer count of minor units, no separators, no exponent.",
          "pattern": "^-?(0|[1-9][0-9]{0,18})$",
          "examples": [
            "150000"
          ]
        },
        "currency": {
          "type": "string",
          "description": "ISO-4217 alphabetic currency code.",
          "pattern": "^[A-Z]{3}$",
          "examples": [
            "EUR"
          ]
        }
      }
    },
    "evidence": {
      "description": "An immutable rule from a digest-verified published artifact.",
      "type": "object",
      "additionalProperties": false,
      "required": [
        "id",
        "taxKey",
        "effectiveFrom",
        "effectiveUntil",
        "rateNumerator",
        "rateDenominator",
        "sourceVersion",
        "artifactSha256"
      ],
      "properties": {
        "id": {
          "type": "string",
          "maxLength": 128
        },
        "taxKey": {
          "type": "string",
          "maxLength": 32
        },
        "effectiveFrom": {
          "type": "string",
          "format": "date"
        },
        "effectiveUntil": {
          "type": [
            "string",
            "null"
          ],
          "format": "date"
        },
        "rateNumerator": {
          "type": "string",
          "pattern": "^[0-9]+$"
        },
        "rateDenominator": {
          "type": "string",
          "pattern": "^[1-9][0-9]*$"
        },
        "sourceVersion": {
          "type": "string",
          "maxLength": 64
        },
        "artifactSha256": {
          "type": "string",
          "pattern": "^[0-9a-f]{64}$"
        }
      }
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

403 · application/problem+json

The caller is authenticated for the tenant but lacks the explicit permission required for this operation. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

limit · query

Maximum number of items to return.

{
  "type": "integer",
  "minimum": 1,
  "maximum": 200,
  "default": 50
}

after · query

Rule ID returned as nextCursor by the previous page.

{
  "type": "string",
  "maxLength": 128
}

200 · application/json

Bounded page of rules, ordered by ID.

Required fields: data, nextCursor

{
  "description": "A bounded page of published reference rules.",
  "type": "object",
  "additionalProperties": false,
  "required": [
    "data",
    "nextCursor"
  ],
  "properties": {
    "data": {
      "type": "array",
      "items": {
        "description": "An immutable rule from a digest-verified published artifact.",
        "type": "object",
        "additionalProperties": false,
        "required": [
          "id",
          "taxKey",
          "effectiveFrom",
          "effectiveUntil",
          "rateNumerator",
          "rateDenominator",
          "sourceVersion",
          "artifactSha256"
        ],
        "properties": {
          "id": {
            "type": "string",
            "maxLength": 128
          },
          "taxKey": {
            "type": "string",
            "maxLength": 32
          },
          "effectiveFrom": {
            "type": "string",
            "format": "date"
          },
          "effectiveUntil": {
            "type": [
              "string",
              "null"
            ],
            "format": "date"
          },
          "rateNumerator": {
            "type": "string",
            "pattern": "^[0-9]+$"
          },
          "rateDenominator": {
            "type": "string",
            "pattern": "^[1-9][0-9]*$"
          },
          "sourceVersion": {
            "type": "string",
            "maxLength": 64
          },
          "artifactSha256": {
            "type": "string",
            "pattern": "^[0-9a-f]{64}$"
          }
        }
      },
      "maxItems": 200
    },
    "nextCursor": {
      "type": [
        "string",
        "null"
      ]
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

403 · application/problem+json

The caller is authenticated for the tenant but lacks the explicit permission required for this operation. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

limit · query

Maximum number of items to return.

{
  "type": "integer",
  "minimum": 1,
  "maximum": 200,
  "default": 50
}

after · query

Exclusive public identifier boundary from nextCursor.

{
  "type": "string",
  "description": "Opaque public tenant identifier.",
  "pattern": "^ten_[0-9A-HJKMNP-TV-Z]{26}$"
}

200 · application/json

The requested access resource.

Required fields: data

{
  "type": "object",
  "description": "One page ordered by public identifier.",
  "additionalProperties": false,
  "required": [
    "data"
  ],
  "properties": {
    "data": {
      "type": "array",
      "items": {
        "type": "object",
        "description": "An isolated accounting tenant within the caller's partner.",
        "additionalProperties": false,
        "required": [
          "id",
          "name",
          "createdAt"
        ],
        "properties": {
          "id": {
            "type": "string",
            "description": "Opaque public tenant identifier.",
            "pattern": "^ten_[0-9A-HJKMNP-TV-Z]{26}$"
          },
          "name": {
            "type": "string"
          },
          "createdAt": {
            "type": "string",
            "format": "date-time"
          }
        }
      }
    },
    "nextCursor": {
      "type": "string",
      "description": "Opaque public tenant identifier.",
      "pattern": "^ten_[0-9A-HJKMNP-TV-Z]{26}$"
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

403 · application/problem+json

The caller is authenticated for the tenant but lacks the explicit permission required for this operation. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

application/json · required

Required fields: name

{
  "type": "object",
  "description": "A new isolated tenant.",
  "additionalProperties": false,
  "required": [
    "name"
  ],
  "properties": {
    "name": {
      "type": "string",
      "minLength": 1,
      "maxLength": 200
    }
  }
}

201 · application/json

The requested access resource.

Required fields: id, name, createdAt

{
  "type": "object",
  "description": "An isolated accounting tenant within the caller's partner.",
  "additionalProperties": false,
  "required": [
    "id",
    "name",
    "createdAt"
  ],
  "properties": {
    "id": {
      "type": "string",
      "description": "Opaque public tenant identifier.",
      "pattern": "^ten_[0-9A-HJKMNP-TV-Z]{26}$"
    },
    "name": {
      "type": "string"
    },
    "createdAt": {
      "type": "string",
      "format": "date-time"
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

403 · application/problem+json

The caller is authenticated for the tenant but lacks the explicit permission required for this operation. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

tenantId · path · required

Opaque public tenant identifier.

{
  "type": "string",
  "description": "Opaque public tenant identifier.",
  "pattern": "^ten_[0-9A-HJKMNP-TV-Z]{26}$"
}

limit · query

Maximum number of items to return.

{
  "type": "integer",
  "minimum": 1,
  "maximum": 200,
  "default": 50
}

after · query

Exclusive public identifier boundary from nextCursor.

{
  "type": "string",
  "description": "Opaque public membership identifier.",
  "pattern": "^mem_[0-9A-HJKMNP-TV-Z]{26}$"
}

200 · application/json

The requested access resource.

Required fields: data

{
  "type": "object",
  "description": "One page ordered by public identifier.",
  "additionalProperties": false,
  "required": [
    "data"
  ],
  "properties": {
    "data": {
      "type": "array",
      "items": {
        "type": "object",
        "description": "An external subject's explicit grants in a tenant.",
        "additionalProperties": false,
        "required": [
          "id",
          "subject",
          "permissions",
          "status",
          "revision",
          "createdAt"
        ],
        "properties": {
          "id": {
            "type": "string",
            "description": "Opaque public membership identifier.",
            "pattern": "^mem_[0-9A-HJKMNP-TV-Z]{26}$"
          },
          "subject": {
            "type": "string"
          },
          "permissions": {
            "type": "array",
            "description": "Explicit unique grants; an empty array grants no operations.",
            "maxItems": 9,
            "uniqueItems": true,
            "items": {
              "type": "string",
              "description": "A local membership grant. access.manage is explicit partner-wide administration.",
              "enum": [
                "accounting.read",
                "accounting.write",
                "documents.read",
                "documents.write",
                "periods.close",
                "webhooks.manage",
                "access.manage",
                "exports.read",
                "audit.read"
              ]
            }
          },
          "status": {
            "type": "string",
            "description": "An inactive membership cannot bind to an API request.",
            "enum": [
              "active",
              "inactive"
            ]
          },
          "revision": {
            "type": "integer",
            "minimum": 1,
            "maximum": 2147483647
          },
          "createdAt": {
            "type": "string",
            "format": "date-time"
          }
        }
      }
    },
    "nextCursor": {
      "type": "string",
      "description": "Opaque public membership identifier.",
      "pattern": "^mem_[0-9A-HJKMNP-TV-Z]{26}$"
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

403 · application/problem+json

The caller is authenticated for the tenant but lacks the explicit permission required for this operation. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

tenantId · path · required

Opaque public tenant identifier.

{
  "type": "string",
  "description": "Opaque public tenant identifier.",
  "pattern": "^ten_[0-9A-HJKMNP-TV-Z]{26}$"
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

application/json · required

Required fields: subject, permissions

{
  "type": "object",
  "description": "Explicit grants for a subject in the administrator's trusted issuer.",
  "additionalProperties": false,
  "required": [
    "subject",
    "permissions"
  ],
  "properties": {
    "subject": {
      "type": "string",
      "minLength": 1,
      "maxLength": 512
    },
    "permissions": {
      "type": "array",
      "description": "Explicit unique grants; an empty array grants no operations.",
      "maxItems": 9,
      "uniqueItems": true,
      "items": {
        "type": "string",
        "description": "A local membership grant. access.manage is explicit partner-wide administration.",
        "enum": [
          "accounting.read",
          "accounting.write",
          "documents.read",
          "documents.write",
          "periods.close",
          "webhooks.manage",
          "access.manage",
          "exports.read",
          "audit.read"
        ]
      }
    }
  }
}

201 · application/json

The requested access resource.

Required fields: id, subject, permissions, status, revision, createdAt

{
  "type": "object",
  "description": "An external subject's explicit grants in a tenant.",
  "additionalProperties": false,
  "required": [
    "id",
    "subject",
    "permissions",
    "status",
    "revision",
    "createdAt"
  ],
  "properties": {
    "id": {
      "type": "string",
      "description": "Opaque public membership identifier.",
      "pattern": "^mem_[0-9A-HJKMNP-TV-Z]{26}$"
    },
    "subject": {
      "type": "string"
    },
    "permissions": {
      "type": "array",
      "description": "Explicit unique grants; an empty array grants no operations.",
      "maxItems": 9,
      "uniqueItems": true,
      "items": {
        "type": "string",
        "description": "A local membership grant. access.manage is explicit partner-wide administration.",
        "enum": [
          "accounting.read",
          "accounting.write",
          "documents.read",
          "documents.write",
          "periods.close",
          "webhooks.manage",
          "access.manage",
          "exports.read",
          "audit.read"
        ]
      }
    },
    "status": {
      "type": "string",
      "description": "An inactive membership cannot bind to an API request.",
      "enum": [
        "active",
        "inactive"
      ]
    },
    "revision": {
      "type": "integer",
      "minimum": 1,
      "maximum": 2147483647
    },
    "createdAt": {
      "type": "string",
      "format": "date-time"
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

403 · application/problem+json

The caller is authenticated for the tenant but lacks the explicit permission required for this operation. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

tenantId · path · required

Opaque public tenant identifier.

{
  "type": "string",
  "description": "Opaque public tenant identifier.",
  "pattern": "^ten_[0-9A-HJKMNP-TV-Z]{26}$"
}

membershipId · path · required

Opaque public membership identifier.

{
  "type": "string",
  "description": "Opaque public membership identifier.",
  "pattern": "^mem_[0-9A-HJKMNP-TV-Z]{26}$"
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

application/json · required

Required fields: permissions, status, expectedRevision

{
  "type": "object",
  "description": "Complete grant replacement or revocation guarded by the current revision.",
  "additionalProperties": false,
  "required": [
    "permissions",
    "status",
    "expectedRevision"
  ],
  "properties": {
    "permissions": {
      "type": "array",
      "description": "Explicit unique grants; an empty array grants no operations.",
      "maxItems": 9,
      "uniqueItems": true,
      "items": {
        "type": "string",
        "description": "A local membership grant. access.manage is explicit partner-wide administration.",
        "enum": [
          "accounting.read",
          "accounting.write",
          "documents.read",
          "documents.write",
          "periods.close",
          "webhooks.manage",
          "access.manage",
          "exports.read",
          "audit.read"
        ]
      }
    },
    "status": {
      "type": "string",
      "description": "An inactive membership cannot bind to an API request.",
      "enum": [
        "active",
        "inactive"
      ]
    },
    "expectedRevision": {
      "type": "integer",
      "minimum": 1,
      "maximum": 2147483647
    }
  }
}

200 · application/json

The requested access resource.

Required fields: id, subject, permissions, status, revision, createdAt

{
  "type": "object",
  "description": "An external subject's explicit grants in a tenant.",
  "additionalProperties": false,
  "required": [
    "id",
    "subject",
    "permissions",
    "status",
    "revision",
    "createdAt"
  ],
  "properties": {
    "id": {
      "type": "string",
      "description": "Opaque public membership identifier.",
      "pattern": "^mem_[0-9A-HJKMNP-TV-Z]{26}$"
    },
    "subject": {
      "type": "string"
    },
    "permissions": {
      "type": "array",
      "description": "Explicit unique grants; an empty array grants no operations.",
      "maxItems": 9,
      "uniqueItems": true,
      "items": {
        "type": "string",
        "description": "A local membership grant. access.manage is explicit partner-wide administration.",
        "enum": [
          "accounting.read",
          "accounting.write",
          "documents.read",
          "documents.write",
          "periods.close",
          "webhooks.manage",
          "access.manage",
          "exports.read",
          "audit.read"
        ]
      }
    },
    "status": {
      "type": "string",
      "description": "An inactive membership cannot bind to an API request.",
      "enum": [
        "active",
        "inactive"
      ]
    },
    "revision": {
      "type": "integer",
      "minimum": 1,
      "maximum": 2147483647
    },
    "createdAt": {
      "type": "string",
      "format": "date-time"
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

403 · application/problem+json

The caller is authenticated for the tenant but lacks the explicit permission required for this operation. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

limit · query

Maximum number of items to return.

{
  "type": "integer",
  "minimum": 1,
  "maximum": 200,
  "default": 50
}

after · query

Return items after this webhook endpoint — the `nextCursor` of the previous page.

{
  "type": "string",
  "description": "Opaque webhook endpoint identifier. It encodes neither the tenant nor the\nendpoint's internal database identity.\n",
  "pattern": "^whep_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "whep_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

200 · application/json

A page of webhook endpoint metadata. Collection responses do not carry per-item HTTP validators; fetch an item before mutating it to obtain its current `ETag`.

Required fields: data

{
  "type": "object",
  "description": "One page of webhook endpoints, oldest creation time first.",
  "required": [
    "data"
  ],
  "additionalProperties": false,
  "properties": {
    "data": {
      "type": "array",
      "items": {
        "type": "object",
        "description": "Safe webhook endpoint metadata. Signing-secret material is never present.",
        "required": [
          "id",
          "url",
          "eventTypes",
          "active",
          "createdAt",
          "updatedAt"
        ],
        "additionalProperties": false,
        "properties": {
          "id": {
            "type": "string",
            "description": "Opaque webhook endpoint identifier. It encodes neither the tenant nor the\nendpoint's internal database identity.\n",
            "pattern": "^whep_[0-9A-HJKMNP-TV-Z]{26}$",
            "examples": [
              "whep_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
            ]
          },
          "url": {
            "type": "string",
            "format": "uri",
            "pattern": "^[hH][tT][tT][pP][sS]://",
            "maxLength": 2048,
            "description": "Absolute HTTPS delivery URL of at most 2,048 UTF-8 bytes. Userinfo and\nfragments are forbidden, and an IP-literal host must be globally routable;\nloopback, private, link-local, carrier-grade NAT, multicast, documentation,\nunspecified, and other special-use addresses are rejected. On create and\nreplacement, the service canonicalizes an accepted URL before storing and\nreturning it: the scheme and ASCII host are lowercased, the default HTTPS\nport is removed, and a non-default port is normalized to decimal. The caller\ndoes not need to perform that canonicalization first.\n\nDNS names are resolved only when delivery is attempted: the complete answer\nset is validated and the selected public address pinned before every connection\nto prevent rebinding. Redirects are not followed. URL syntax and IP-literal\nrestrictions are rechecked whenever metadata is replaced and again at delivery\ntime. Query strings are retained in immutable routing history for audit and\nretries; they must not contain credentials or capability tokens. Authenticate\ndelivery with the signing secret instead.\n",
            "examples": [
              "https://hooks.example.com/accounting"
            ]
          },
          "eventTypes": {
            "type": "array",
            "maxItems": 16,
            "uniqueItems": true,
            "description": "Unique event types delivered to this endpoint, with at most 16 entries.\nAn empty array subscribes the endpoint to all current and future webhook\nevent types; list explicit values to opt in only to those event types. The\nsubscription is evaluated when each event's recipients are snapshotted;\nchanging it does not add or remove recipients from an existing snapshot.\n",
            "items": {
              "type": "string",
              "description": "A domain event type currently available for endpoint subscriptions.",
              "enum": [
                "journal_entry.posted"
              ],
              "x-enum-varnames": [
                "WebhookEventTypeJournalEntryPosted"
              ]
            }
          },
          "active": {
            "type": "boolean",
            "description": "Whether this endpoint is eligible for newly committed event snapshots.\nDeactivation also permanently suppresses its older-snapshot recipients\nthat a worker has not already loaded; later reactivation does not revive\nthose recipients.\n"
          },
          "createdAt": {
            "type": "string",
            "format": "date-time"
          },
          "updatedAt": {
            "type": "string",
            "format": "date-time",
            "description": "Last metadata, active-state, or secret change. A secret rotation changes\nthis timestamp but never exposes either secret.\n"
          }
        }
      }
    },
    "nextCursor": {
      "type": "string",
      "description": "Opaque webhook endpoint identifier. It encodes neither the tenant nor the\nendpoint's internal database identity.\n",
      "pattern": "^whep_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "whep_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

403 · application/problem+json

The caller is authenticated for the tenant but lacks the explicit permission required for this operation. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

application/json · required

Required fields: url, eventTypes, secret

{
  "type": "object",
  "description": "Fields accepted when registering an active webhook endpoint.",
  "required": [
    "url",
    "eventTypes",
    "secret"
  ],
  "additionalProperties": false,
  "properties": {
    "url": {
      "type": "string",
      "format": "uri",
      "pattern": "^[hH][tT][tT][pP][sS]://",
      "maxLength": 2048,
      "description": "Absolute HTTPS delivery URL of at most 2,048 UTF-8 bytes. Userinfo and\nfragments are forbidden, and an IP-literal host must be globally routable;\nloopback, private, link-local, carrier-grade NAT, multicast, documentation,\nunspecified, and other special-use addresses are rejected. On create and\nreplacement, the service canonicalizes an accepted URL before storing and\nreturning it: the scheme and ASCII host are lowercased, the default HTTPS\nport is removed, and a non-default port is normalized to decimal. The caller\ndoes not need to perform that canonicalization first.\n\nDNS names are resolved only when delivery is attempted: the complete answer\nset is validated and the selected public address pinned before every connection\nto prevent rebinding. Redirects are not followed. URL syntax and IP-literal\nrestrictions are rechecked whenever metadata is replaced and again at delivery\ntime. Query strings are retained in immutable routing history for audit and\nretries; they must not contain credentials or capability tokens. Authenticate\ndelivery with the signing secret instead.\n",
      "examples": [
        "https://hooks.example.com/accounting"
      ]
    },
    "eventTypes": {
      "type": "array",
      "maxItems": 16,
      "uniqueItems": true,
      "description": "Unique event types delivered to this endpoint, with at most 16 entries.\nAn empty array subscribes the endpoint to all current and future webhook\nevent types; list explicit values to opt in only to those event types. The\nsubscription is evaluated when each event's recipients are snapshotted;\nchanging it does not add or remove recipients from an existing snapshot.\n",
      "items": {
        "type": "string",
        "description": "A domain event type currently available for endpoint subscriptions.",
        "enum": [
          "journal_entry.posted"
        ],
        "x-enum-varnames": [
          "WebhookEventTypeJournalEntryPosted"
        ]
      }
    },
    "secret": {
      "type": "string",
      "minLength": 43,
      "maxLength": 43,
      "pattern": "^[A-Za-z0-9_-]{42}[AEIMQUYcgkosw048]$",
      "writeOnly": true,
      "x-go-type-skip-optional-pointer": true,
      "description": "Exactly 32 bytes encoded as canonical, unpadded base64url (43 characters).\nFor every create or rotation, the caller MUST generate a unique, independent,\nunpredictable 32-byte value with a cryptographically secure random-number\ngenerator and MUST NOT reuse it for another endpoint or secret version. The\ncaller retains this HMAC-SHA256 signing secret. It is accepted only on create\nor rotation and is never returned by the API. The final-character restriction\nrejects non-canonical encodings with non-zero unused bits.\n"
    }
  }
}

201 · application/json

The created endpoint metadata. The signing secret is never returned.

Required fields: id, url, eventTypes, active, createdAt, updatedAt

{
  "type": "object",
  "description": "Safe webhook endpoint metadata. Signing-secret material is never present.",
  "required": [
    "id",
    "url",
    "eventTypes",
    "active",
    "createdAt",
    "updatedAt"
  ],
  "additionalProperties": false,
  "properties": {
    "id": {
      "type": "string",
      "description": "Opaque webhook endpoint identifier. It encodes neither the tenant nor the\nendpoint's internal database identity.\n",
      "pattern": "^whep_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "whep_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "url": {
      "type": "string",
      "format": "uri",
      "pattern": "^[hH][tT][tT][pP][sS]://",
      "maxLength": 2048,
      "description": "Absolute HTTPS delivery URL of at most 2,048 UTF-8 bytes. Userinfo and\nfragments are forbidden, and an IP-literal host must be globally routable;\nloopback, private, link-local, carrier-grade NAT, multicast, documentation,\nunspecified, and other special-use addresses are rejected. On create and\nreplacement, the service canonicalizes an accepted URL before storing and\nreturning it: the scheme and ASCII host are lowercased, the default HTTPS\nport is removed, and a non-default port is normalized to decimal. The caller\ndoes not need to perform that canonicalization first.\n\nDNS names are resolved only when delivery is attempted: the complete answer\nset is validated and the selected public address pinned before every connection\nto prevent rebinding. Redirects are not followed. URL syntax and IP-literal\nrestrictions are rechecked whenever metadata is replaced and again at delivery\ntime. Query strings are retained in immutable routing history for audit and\nretries; they must not contain credentials or capability tokens. Authenticate\ndelivery with the signing secret instead.\n",
      "examples": [
        "https://hooks.example.com/accounting"
      ]
    },
    "eventTypes": {
      "type": "array",
      "maxItems": 16,
      "uniqueItems": true,
      "description": "Unique event types delivered to this endpoint, with at most 16 entries.\nAn empty array subscribes the endpoint to all current and future webhook\nevent types; list explicit values to opt in only to those event types. The\nsubscription is evaluated when each event's recipients are snapshotted;\nchanging it does not add or remove recipients from an existing snapshot.\n",
      "items": {
        "type": "string",
        "description": "A domain event type currently available for endpoint subscriptions.",
        "enum": [
          "journal_entry.posted"
        ],
        "x-enum-varnames": [
          "WebhookEventTypeJournalEntryPosted"
        ]
      }
    },
    "active": {
      "type": "boolean",
      "description": "Whether this endpoint is eligible for newly committed event snapshots.\nDeactivation also permanently suppresses its older-snapshot recipients\nthat a worker has not already loaded; later reactivation does not revive\nthose recipients.\n"
    },
    "createdAt": {
      "type": "string",
      "format": "date-time"
    },
    "updatedAt": {
      "type": "string",
      "format": "date-time",
      "description": "Last metadata, active-state, or secret change. A secret rotation changes\nthis timestamp but never exposes either secret.\n"
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

403 · application/problem+json

The caller is authenticated for the tenant but lacks the explicit permission required for this operation. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

webhookEndpointId · path · required

Identifier of the tenant-managed webhook endpoint.

{
  "type": "string",
  "description": "Opaque webhook endpoint identifier. It encodes neither the tenant nor the\nendpoint's internal database identity.\n",
  "pattern": "^whep_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "whep_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

If-Match · header · required

The exact strong `ETag` returned by the latest item response. Weak tags, wildcard matching, and validator lists are not accepted because every mutation must name one observed endpoint version. A missing precondition is `428 precondition-required`; a well-formed but stale validator is `412 precondition-failed`. After a 412, fetch the item and retry the intended change with its new `ETag` and a fresh `Idempotency-Key`.

{
  "type": "string",
  "pattern": "^\"whep-v1-[A-Za-z0-9_-]{32}\"$"
}

Example

"\"whep-v1-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\""

204

The endpoint is inactive and its audit history is preserved.

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

403 · application/problem+json

The caller is authenticated for the tenant but lacks the explicit permission required for this operation. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

412 · application/problem+json

The supplied `If-Match` validator is well-formed but stale. No resource state or audit evidence was changed. Fetch the item and retry the intended change with its new `ETag` and a fresh `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

428 · application/problem+json

This mutation requires the latest item `ETag` in `If-Match`; no resource state or audit evidence was changed.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

webhookEndpointId · path · required

Identifier of the tenant-managed webhook endpoint.

{
  "type": "string",
  "description": "Opaque webhook endpoint identifier. It encodes neither the tenant nor the\nendpoint's internal database identity.\n",
  "pattern": "^whep_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "whep_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

200 · application/json

The webhook endpoint metadata.

Required fields: id, url, eventTypes, active, createdAt, updatedAt

{
  "type": "object",
  "description": "Safe webhook endpoint metadata. Signing-secret material is never present.",
  "required": [
    "id",
    "url",
    "eventTypes",
    "active",
    "createdAt",
    "updatedAt"
  ],
  "additionalProperties": false,
  "properties": {
    "id": {
      "type": "string",
      "description": "Opaque webhook endpoint identifier. It encodes neither the tenant nor the\nendpoint's internal database identity.\n",
      "pattern": "^whep_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "whep_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "url": {
      "type": "string",
      "format": "uri",
      "pattern": "^[hH][tT][tT][pP][sS]://",
      "maxLength": 2048,
      "description": "Absolute HTTPS delivery URL of at most 2,048 UTF-8 bytes. Userinfo and\nfragments are forbidden, and an IP-literal host must be globally routable;\nloopback, private, link-local, carrier-grade NAT, multicast, documentation,\nunspecified, and other special-use addresses are rejected. On create and\nreplacement, the service canonicalizes an accepted URL before storing and\nreturning it: the scheme and ASCII host are lowercased, the default HTTPS\nport is removed, and a non-default port is normalized to decimal. The caller\ndoes not need to perform that canonicalization first.\n\nDNS names are resolved only when delivery is attempted: the complete answer\nset is validated and the selected public address pinned before every connection\nto prevent rebinding. Redirects are not followed. URL syntax and IP-literal\nrestrictions are rechecked whenever metadata is replaced and again at delivery\ntime. Query strings are retained in immutable routing history for audit and\nretries; they must not contain credentials or capability tokens. Authenticate\ndelivery with the signing secret instead.\n",
      "examples": [
        "https://hooks.example.com/accounting"
      ]
    },
    "eventTypes": {
      "type": "array",
      "maxItems": 16,
      "uniqueItems": true,
      "description": "Unique event types delivered to this endpoint, with at most 16 entries.\nAn empty array subscribes the endpoint to all current and future webhook\nevent types; list explicit values to opt in only to those event types. The\nsubscription is evaluated when each event's recipients are snapshotted;\nchanging it does not add or remove recipients from an existing snapshot.\n",
      "items": {
        "type": "string",
        "description": "A domain event type currently available for endpoint subscriptions.",
        "enum": [
          "journal_entry.posted"
        ],
        "x-enum-varnames": [
          "WebhookEventTypeJournalEntryPosted"
        ]
      }
    },
    "active": {
      "type": "boolean",
      "description": "Whether this endpoint is eligible for newly committed event snapshots.\nDeactivation also permanently suppresses its older-snapshot recipients\nthat a worker has not already loaded; later reactivation does not revive\nthose recipients.\n"
    },
    "createdAt": {
      "type": "string",
      "format": "date-time"
    },
    "updatedAt": {
      "type": "string",
      "format": "date-time",
      "description": "Last metadata, active-state, or secret change. A secret rotation changes\nthis timestamp but never exposes either secret.\n"
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

403 · application/problem+json

The caller is authenticated for the tenant but lacks the explicit permission required for this operation. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

webhookEndpointId · path · required

Identifier of the tenant-managed webhook endpoint.

{
  "type": "string",
  "description": "Opaque webhook endpoint identifier. It encodes neither the tenant nor the\nendpoint's internal database identity.\n",
  "pattern": "^whep_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "whep_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

If-Match · header · required

The exact strong `ETag` returned by the latest item response. Weak tags, wildcard matching, and validator lists are not accepted because every mutation must name one observed endpoint version. A missing precondition is `428 precondition-required`; a well-formed but stale validator is `412 precondition-failed`. After a 412, fetch the item and retry the intended change with its new `ETag` and a fresh `Idempotency-Key`.

{
  "type": "string",
  "pattern": "^\"whep-v1-[A-Za-z0-9_-]{32}\"$"
}

Example

"\"whep-v1-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\""

application/json · required

Required fields: url, eventTypes, active

{
  "type": "object",
  "description": "Complete replacement of mutable endpoint metadata. The signing secret is\ndeliberately not metadata and remains unchanged.\n",
  "required": [
    "url",
    "eventTypes",
    "active"
  ],
  "additionalProperties": false,
  "properties": {
    "url": {
      "type": "string",
      "format": "uri",
      "pattern": "^[hH][tT][tT][pP][sS]://",
      "maxLength": 2048,
      "description": "Absolute HTTPS delivery URL of at most 2,048 UTF-8 bytes. Userinfo and\nfragments are forbidden, and an IP-literal host must be globally routable;\nloopback, private, link-local, carrier-grade NAT, multicast, documentation,\nunspecified, and other special-use addresses are rejected. On create and\nreplacement, the service canonicalizes an accepted URL before storing and\nreturning it: the scheme and ASCII host are lowercased, the default HTTPS\nport is removed, and a non-default port is normalized to decimal. The caller\ndoes not need to perform that canonicalization first.\n\nDNS names are resolved only when delivery is attempted: the complete answer\nset is validated and the selected public address pinned before every connection\nto prevent rebinding. Redirects are not followed. URL syntax and IP-literal\nrestrictions are rechecked whenever metadata is replaced and again at delivery\ntime. Query strings are retained in immutable routing history for audit and\nretries; they must not contain credentials or capability tokens. Authenticate\ndelivery with the signing secret instead.\n",
      "examples": [
        "https://hooks.example.com/accounting"
      ]
    },
    "eventTypes": {
      "type": "array",
      "maxItems": 16,
      "uniqueItems": true,
      "description": "Unique event types delivered to this endpoint, with at most 16 entries.\nAn empty array subscribes the endpoint to all current and future webhook\nevent types; list explicit values to opt in only to those event types. The\nsubscription is evaluated when each event's recipients are snapshotted;\nchanging it does not add or remove recipients from an existing snapshot.\n",
      "items": {
        "type": "string",
        "description": "A domain event type currently available for endpoint subscriptions.",
        "enum": [
          "journal_entry.posted"
        ],
        "x-enum-varnames": [
          "WebhookEventTypeJournalEntryPosted"
        ]
      }
    },
    "active": {
      "type": "boolean"
    }
  }
}

200 · application/json

The replaced webhook endpoint metadata.

Required fields: id, url, eventTypes, active, createdAt, updatedAt

{
  "type": "object",
  "description": "Safe webhook endpoint metadata. Signing-secret material is never present.",
  "required": [
    "id",
    "url",
    "eventTypes",
    "active",
    "createdAt",
    "updatedAt"
  ],
  "additionalProperties": false,
  "properties": {
    "id": {
      "type": "string",
      "description": "Opaque webhook endpoint identifier. It encodes neither the tenant nor the\nendpoint's internal database identity.\n",
      "pattern": "^whep_[0-9A-HJKMNP-TV-Z]{26}$",
      "examples": [
        "whep_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
      ]
    },
    "url": {
      "type": "string",
      "format": "uri",
      "pattern": "^[hH][tT][tT][pP][sS]://",
      "maxLength": 2048,
      "description": "Absolute HTTPS delivery URL of at most 2,048 UTF-8 bytes. Userinfo and\nfragments are forbidden, and an IP-literal host must be globally routable;\nloopback, private, link-local, carrier-grade NAT, multicast, documentation,\nunspecified, and other special-use addresses are rejected. On create and\nreplacement, the service canonicalizes an accepted URL before storing and\nreturning it: the scheme and ASCII host are lowercased, the default HTTPS\nport is removed, and a non-default port is normalized to decimal. The caller\ndoes not need to perform that canonicalization first.\n\nDNS names are resolved only when delivery is attempted: the complete answer\nset is validated and the selected public address pinned before every connection\nto prevent rebinding. Redirects are not followed. URL syntax and IP-literal\nrestrictions are rechecked whenever metadata is replaced and again at delivery\ntime. Query strings are retained in immutable routing history for audit and\nretries; they must not contain credentials or capability tokens. Authenticate\ndelivery with the signing secret instead.\n",
      "examples": [
        "https://hooks.example.com/accounting"
      ]
    },
    "eventTypes": {
      "type": "array",
      "maxItems": 16,
      "uniqueItems": true,
      "description": "Unique event types delivered to this endpoint, with at most 16 entries.\nAn empty array subscribes the endpoint to all current and future webhook\nevent types; list explicit values to opt in only to those event types. The\nsubscription is evaluated when each event's recipients are snapshotted;\nchanging it does not add or remove recipients from an existing snapshot.\n",
      "items": {
        "type": "string",
        "description": "A domain event type currently available for endpoint subscriptions.",
        "enum": [
          "journal_entry.posted"
        ],
        "x-enum-varnames": [
          "WebhookEventTypeJournalEntryPosted"
        ]
      }
    },
    "active": {
      "type": "boolean",
      "description": "Whether this endpoint is eligible for newly committed event snapshots.\nDeactivation also permanently suppresses its older-snapshot recipients\nthat a worker has not already loaded; later reactivation does not revive\nthose recipients.\n"
    },
    "createdAt": {
      "type": "string",
      "format": "date-time"
    },
    "updatedAt": {
      "type": "string",
      "format": "date-time",
      "description": "Last metadata, active-state, or secret change. A secret rotation changes\nthis timestamp but never exposes either secret.\n"
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

403 · application/problem+json

The caller is authenticated for the tenant but lacks the explicit permission required for this operation. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

412 · application/problem+json

The supplied `If-Match` validator is well-formed but stale. No resource state or audit evidence was changed. Fetch the item and retry the intended change with its new `ETag` and a fresh `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

428 · application/problem+json

This mutation requires the latest item `ETag` in `If-Match`; no resource state or audit evidence was changed.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

webhookEndpointId · path · required

Identifier of the tenant-managed webhook endpoint.

{
  "type": "string",
  "description": "Opaque webhook endpoint identifier. It encodes neither the tenant nor the\nendpoint's internal database identity.\n",
  "pattern": "^whep_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "whep_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

Idempotency-Key · header · required

Client-generated key that makes this mutation replay-safe. Send exactly one field value. Use a fresh value (a UUID or equivalent) per logical operation and reuse it verbatim when retrying that operation. One layer of surrounding double quotes is stripped before the key is compared, so the RFC 8941 structured-field form (`"k"`) and the bare form (`k`) name the same key.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 255
}

Example

"2f1c7f6e-5f0b-4a3a-8f8f-2b8f6c1f9a11"

X-Accounting-Acting-User-Issuer · header

Optional partner-attested human attribution, machine authentication only. Send exactly one value together with X-Accounting-Acting-User-Subject. Absolute HTTPS issuer URI without credentials, query or fragment; ASCII without whitespace or commas. The authenticated partner asserts this identity; Accounting does not independently verify a human login token. This metadata grants no tenant access or permissions and never replaces the authenticated machine membership. Retained as immutable same-transaction evidence with the write and included in the idempotency fingerprint. Successful attributed writes and their replays return X-Accounting-Acting-User-Recorded: v1. Deploy this API before enabling attributed writes; a missing acknowledgment leaves the outcome unqualified.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^https://[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"https://auth.d0.eu"

X-Accounting-Acting-User-Subject · header

Stable opaque person reference in the issuer namespace, asserted by the authenticated partner. Send exactly one value together with X-Accounting-Acting-User-Issuer; 1–200 ASCII bytes without whitespace or commas. Use technical references, not names or email addresses. A different attributed human or asserting machine under the same Idempotency-Key is a different request (422). Neither header is an Accounting membership ID.

{
  "type": "string",
  "minLength": 1,
  "maxLength": 200,
  "pattern": "^[\\x21-\\x2B\\x2D-\\x7E]+$"
}

Example

"person-42"

If-Match · header · required

The exact strong `ETag` returned by the latest item response. Weak tags, wildcard matching, and validator lists are not accepted because every mutation must name one observed endpoint version. A missing precondition is `428 precondition-required`; a well-formed but stale validator is `412 precondition-failed`. After a 412, fetch the item and retry the intended change with its new `ETag` and a fresh `Idempotency-Key`.

{
  "type": "string",
  "pattern": "^\"whep-v1-[A-Za-z0-9_-]{32}\"$"
}

Example

"\"whep-v1-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\""

application/json · required

Required fields: secret

{
  "type": "object",
  "description": "Write-only replacement signing material for one endpoint.",
  "required": [
    "secret"
  ],
  "additionalProperties": false,
  "properties": {
    "secret": {
      "type": "string",
      "minLength": 43,
      "maxLength": 43,
      "pattern": "^[A-Za-z0-9_-]{42}[AEIMQUYcgkosw048]$",
      "writeOnly": true,
      "x-go-type-skip-optional-pointer": true,
      "description": "Exactly 32 bytes encoded as canonical, unpadded base64url (43 characters).\nFor every create or rotation, the caller MUST generate a unique, independent,\nunpredictable 32-byte value with a cryptographically secure random-number\ngenerator and MUST NOT reuse it for another endpoint or secret version. The\ncaller retains this HMAC-SHA256 signing secret. It is accepted only on create\nor rotation and is never returned by the API. The final-character restriction\nrejects non-canonical encodings with non-zero unused bits.\n"
    }
  }
}

204

Future delivery attempts use the replacement secret.

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

403 · application/problem+json

The caller is authenticated for the tenant but lacks the explicit permission required for this operation. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

409 · application/problem+json

The request conflicts with current state — a duplicate, a sealed period, an entry that is no longer a draft, or an in-flight request with this `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

412 · application/problem+json

The supplied `If-Match` validator is well-formed but stale. No resource state or audit evidence was changed. Fetch the item and retry the intended change with its new `ETag` and a fresh `Idempotency-Key`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

422 · application/problem+json

The request is well-formed but cannot be carried out — an unbalanced Buchung, or an `Idempotency-Key` reused with a different request (including a different `Content-Type` or `If-Match` validator).

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

428 · application/problem+json

This mutation requires the latest item `ETag` in `If-Match`; no resource state or audit evidence was changed.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

zugferdPdfId · path · required

Identifier of the durable ZUGFeRD PDF generation.

{
  "type": "string",
  "description": "Opaque durable ZUGFeRD PDF generation identifier.",
  "pattern": "^eip_[0-9A-HJKMNP-TV-Z]{26}$",
  "examples": [
    "eip_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
  ]
}

200 · application/json

The generation and its current state.

{
  "description": "Durable ZUGFeRD PDF state. Pending has neither result nor failure;\ncompleted has the new immutable output Beleg and exact generation evidence;\nfailed exposes only a stable public failure code.\n",
  "oneOf": [
    {
      "type": "object",
      "description": "A durable generation waiting for processing or a retry.",
      "required": [
        "id",
        "validationId",
        "invoiceDocumentId",
        "visualDocumentId",
        "target",
        "recipe",
        "status",
        "requestedAt"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "type": "string",
          "description": "Opaque durable ZUGFeRD PDF generation identifier.",
          "pattern": "^eip_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "eip_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "validationId": {
          "type": "string",
          "description": "Opaque durable e-invoice validation identifier.",
          "pattern": "^eiv_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "eiv_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "invoiceDocumentId": {
          "type": "string",
          "description": "Opaque Beleg identifier. It does not encode storage identity.",
          "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "visualDocumentId": {
          "type": "string",
          "description": "Opaque Beleg identifier. It does not encode storage identity.",
          "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "target": {
          "type": "object",
          "description": "Frozen standard and profile selected by trusted server configuration.",
          "required": [
            "name",
            "version",
            "profile"
          ],
          "additionalProperties": false,
          "properties": {
            "name": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            },
            "version": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            },
            "profile": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            }
          }
        },
        "recipe": {
          "type": "object",
          "description": "Frozen versioned generation recipe selected by trusted server configuration.",
          "required": [
            "name",
            "version"
          ],
          "additionalProperties": false,
          "properties": {
            "name": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            },
            "version": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            }
          }
        },
        "status": {
          "type": "string",
          "const": "pending",
          "x-enum-varnames": [
            "ZUGFeRDPDFPendingStatusPending"
          ]
        },
        "requestedAt": {
          "type": "string",
          "format": "date-time"
        }
      }
    },
    {
      "type": "object",
      "description": "A terminal generation with immutable output and provenance evidence.",
      "required": [
        "id",
        "validationId",
        "invoiceDocumentId",
        "visualDocumentId",
        "target",
        "recipe",
        "status",
        "requestedAt",
        "completedAt",
        "outputDocument",
        "result"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "type": "string",
          "description": "Opaque durable ZUGFeRD PDF generation identifier.",
          "pattern": "^eip_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "eip_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "validationId": {
          "type": "string",
          "description": "Opaque durable e-invoice validation identifier.",
          "pattern": "^eiv_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "eiv_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "invoiceDocumentId": {
          "type": "string",
          "description": "Opaque Beleg identifier. It does not encode storage identity.",
          "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "visualDocumentId": {
          "type": "string",
          "description": "Opaque Beleg identifier. It does not encode storage identity.",
          "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "target": {
          "type": "object",
          "description": "Frozen standard and profile selected by trusted server configuration.",
          "required": [
            "name",
            "version",
            "profile"
          ],
          "additionalProperties": false,
          "properties": {
            "name": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            },
            "version": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            },
            "profile": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            }
          }
        },
        "recipe": {
          "type": "object",
          "description": "Frozen versioned generation recipe selected by trusted server configuration.",
          "required": [
            "name",
            "version"
          ],
          "additionalProperties": false,
          "properties": {
            "name": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            },
            "version": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            }
          }
        },
        "status": {
          "type": "string",
          "const": "completed",
          "x-enum-varnames": [
            "ZUGFeRDPDFCompletedStatusCompleted"
          ]
        },
        "requestedAt": {
          "type": "string",
          "format": "date-time"
        },
        "completedAt": {
          "type": "string",
          "format": "date-time"
        },
        "outputDocument": {
          "type": "object",
          "description": "Public metadata for the completed generation output. This Beleg is always\na newly derived, immutable archived PDF; its exact two-source lineage is\nretained server-side.\n",
          "required": [
            "id",
            "origin",
            "status",
            "originalFilename",
            "mediaType",
            "sizeBytes",
            "contentSha256",
            "documentDate",
            "classification",
            "retentionUntil",
            "createdAt",
            "archivedAt"
          ],
          "additionalProperties": false,
          "properties": {
            "id": {
              "type": "string",
              "description": "Opaque Beleg identifier. It does not encode storage identity.",
              "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
              "examples": [
                "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
              ]
            },
            "origin": {
              "type": "string",
              "const": "derived",
              "x-enum-varnames": [
                "ZUGFeRDPDFDocumentOriginDerived"
              ]
            },
            "status": {
              "type": "string",
              "const": "archived",
              "x-enum-varnames": [
                "ZUGFeRDPDFDocumentStatusArchived"
              ]
            },
            "originalFilename": {
              "type": "string"
            },
            "mediaType": {
              "type": "string",
              "const": "application/pdf",
              "x-enum-varnames": [
                "ZUGFeRDPDFDocumentMediaTypeApplicationPDF"
              ]
            },
            "sizeBytes": {
              "type": "integer",
              "format": "int64",
              "minimum": 1
            },
            "contentSha256": {
              "type": "string",
              "pattern": "^[0-9a-f]{64}$"
            },
            "documentDate": {
              "type": "string",
              "format": "date"
            },
            "classification": {
              "type": "string",
              "description": "Trusted server-assigned Beleg class."
            },
            "retentionUntil": {
              "type": "string",
              "format": "date"
            },
            "createdAt": {
              "type": "string",
              "format": "date-time"
            },
            "archivedAt": {
              "type": "string",
              "format": "date-time"
            }
          }
        },
        "result": {
          "type": "object",
          "description": "Exact immutable generation evidence reported by the sidecar.",
          "required": [
            "schema",
            "invoiceSha256",
            "visualSha256",
            "output",
            "standard",
            "recipe",
            "processor",
            "ruleset"
          ],
          "additionalProperties": false,
          "properties": {
            "schema": {
              "type": "string",
              "const": "devacc.einvoice.zugferd-pdf.v1",
              "x-enum-varnames": [
                "ZUGFeRDPDFResultSchemaV1"
              ]
            },
            "invoiceSha256": {
              "type": "string",
              "pattern": "^[0-9a-f]{64}$"
            },
            "visualSha256": {
              "type": "string",
              "pattern": "^[0-9a-f]{64}$"
            },
            "output": {
              "type": "object",
              "description": "Exact output facts verified before the derived Beleg was archived.",
              "required": [
                "contentId",
                "mediaType",
                "sizeBytes",
                "sha256",
                "pdfConformance",
                "embeddedFilename"
              ],
              "additionalProperties": false,
              "properties": {
                "contentId": {
                  "type": "string",
                  "const": "output",
                  "x-enum-varnames": [
                    "ZUGFeRDPDFOutputContentIdOutput"
                  ]
                },
                "mediaType": {
                  "type": "string",
                  "const": "application/pdf",
                  "x-enum-varnames": [
                    "ZUGFeRDPDFOutputMediaTypeApplicationPDF"
                  ]
                },
                "sizeBytes": {
                  "type": "integer",
                  "format": "int64",
                  "minimum": 1
                },
                "sha256": {
                  "type": "string",
                  "pattern": "^[0-9a-f]{64}$"
                },
                "pdfConformance": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256,
                  "description": "Conformance identity reported by the configured production sidecar.\nThis API records the evidence but does not independently certify it.\n"
                },
                "embeddedFilename": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 255
                }
              }
            },
            "standard": {
              "type": "object",
              "description": "Frozen standard and profile selected by trusted server configuration.",
              "required": [
                "name",
                "version",
                "profile"
              ],
              "additionalProperties": false,
              "properties": {
                "name": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256
                },
                "version": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256
                },
                "profile": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256
                }
              }
            },
            "recipe": {
              "type": "object",
              "description": "Frozen versioned generation recipe selected by trusted server configuration.",
              "required": [
                "name",
                "version"
              ],
              "additionalProperties": false,
              "properties": {
                "name": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256
                },
                "version": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256
                }
              }
            },
            "processor": {
              "type": "object",
              "description": "Opaque ZUGFeRD sidecar runtime or versioned artifact identity.",
              "required": [
                "name",
                "version"
              ],
              "additionalProperties": false,
              "properties": {
                "name": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256
                },
                "version": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256
                }
              }
            },
            "ruleset": {
              "type": "object",
              "description": "Opaque ZUGFeRD sidecar runtime or versioned artifact identity.",
              "required": [
                "name",
                "version"
              ],
              "additionalProperties": false,
              "properties": {
                "name": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256
                },
                "version": {
                  "type": "string",
                  "minLength": 1,
                  "maxLength": 256
                }
              }
            }
          }
        }
      }
    },
    {
      "type": "object",
      "description": "A terminal PDF-generation failure without sensitive diagnostics.",
      "required": [
        "id",
        "validationId",
        "invoiceDocumentId",
        "visualDocumentId",
        "target",
        "recipe",
        "status",
        "requestedAt",
        "completedAt",
        "failure"
      ],
      "additionalProperties": false,
      "properties": {
        "id": {
          "type": "string",
          "description": "Opaque durable ZUGFeRD PDF generation identifier.",
          "pattern": "^eip_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "eip_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "validationId": {
          "type": "string",
          "description": "Opaque durable e-invoice validation identifier.",
          "pattern": "^eiv_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "eiv_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "invoiceDocumentId": {
          "type": "string",
          "description": "Opaque Beleg identifier. It does not encode storage identity.",
          "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "visualDocumentId": {
          "type": "string",
          "description": "Opaque Beleg identifier. It does not encode storage identity.",
          "pattern": "^doc_[0-9A-HJKMNP-TV-Z]{26}$",
          "examples": [
            "doc_9GXQ8W5V4R3P2N1M0KJHGF7ED6"
          ]
        },
        "target": {
          "type": "object",
          "description": "Frozen standard and profile selected by trusted server configuration.",
          "required": [
            "name",
            "version",
            "profile"
          ],
          "additionalProperties": false,
          "properties": {
            "name": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            },
            "version": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            },
            "profile": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            }
          }
        },
        "recipe": {
          "type": "object",
          "description": "Frozen versioned generation recipe selected by trusted server configuration.",
          "required": [
            "name",
            "version"
          ],
          "additionalProperties": false,
          "properties": {
            "name": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            },
            "version": {
              "type": "string",
              "minLength": 1,
              "maxLength": 256
            }
          }
        },
        "status": {
          "type": "string",
          "const": "failed",
          "x-enum-varnames": [
            "ZUGFeRDPDFFailedStatusFailed"
          ]
        },
        "requestedAt": {
          "type": "string",
          "format": "date-time"
        },
        "completedAt": {
          "type": "string",
          "format": "date-time"
        },
        "failure": {
          "type": "object",
          "description": "Stable public failure classification without internal diagnostics.",
          "required": [
            "code"
          ],
          "additionalProperties": false,
          "properties": {
            "code": {
              "type": "string",
              "enum": [
                "unsupported-source",
                "generation-capacity-exceeded"
              ],
              "x-enum-varnames": [
                "ZUGFeRDPDFFailureCodeUnsupportedSource",
                "ZUGFeRDPDFFailureCodeGenerationCapacityExceeded"
              ]
            }
          }
        }
      }
    }
  ],
  "discriminator": {
    "propertyName": "status",
    "mapping": {
      "pending": "#/components/schemas/ZUGFeRDPDFPending",
      "completed": "#/components/schemas/ZUGFeRDPDFCompleted",
      "failed": "#/components/schemas/ZUGFeRDPDFFailed"
    }
  }
}

400 · application/problem+json

The request is malformed or violates the contract.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

401 · application/problem+json

No valid tenant assertion. No data is read or written.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

404 · application/problem+json

No such resource in the calling tenant.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}

default · application/problem+json

An error. Branch on `type`.

Required fields: type, title, status

{
  "type": "object",
  "description": "RFC 9457 problem detail.",
  "required": [
    "type",
    "title",
    "status"
  ],
  "properties": {
    "type": {
      "type": "string",
      "format": "uri",
      "description": "Stable, machine-readable problem identifier. This is the field to\nbranch on; `title` and `detail` are prose and may be reworded.\n",
      "examples": [
        "https://api.d0.eu/accounting/problems/period-sealed"
      ]
    },
    "title": {
      "type": "string",
      "description": "Short human-readable summary of the problem type."
    },
    "status": {
      "type": "integer",
      "minimum": 400,
      "maximum": 599
    },
    "detail": {
      "type": "string",
      "description": "Human-readable explanation specific to this occurrence."
    },
    "instance": {
      "type": "string",
      "format": "uri-reference",
      "description": "The request path this problem occurred on."
    },
    "errors": {
      "type": "array",
      "description": "Field-level detail, when the problem is a validation failure.",
      "items": {
        "type": "object",
        "required": [
          "detail"
        ],
        "properties": {
          "pointer": {
            "type": "string",
            "description": "JSON Pointer (RFC 6901) into the request body.",
            "examples": [
              "/lines/0/amount"
            ]
          },
          "detail": {
            "type": "string"
          }
        }
      }
    }
  }
}