{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://github.com/rogersialves/wendkeep/blob/main/schema/wendkeep.provenance-receipt-v2.schema.json",
  "title": "WendKeep Provenance Receipt v2",
  "description": "A canonical, hash-chained receipt for a provenance-gated operation.",
  "type": "object",
  "additionalProperties": false,
  "required": [
    "schema_version",
    "sequence",
    "receipt_id",
    "previous_hash",
    "receipt_hash",
    "kind",
    "subject",
    "claims",
    "observations",
    "recorded_at"
  ],
  "properties": {
    "schema_version": {
      "const": 2
    },
    "sequence": {
      "type": "integer",
      "minimum": 1
    },
    "receipt_id": {
      "type": "string",
      "pattern": "^sha256:[a-f0-9]{64}$"
    },
    "previous_hash": {
      "type": "string",
      "pattern": "^sha256:[a-f0-9]{64}$",
      "description": "Hash of the previous v2 receipt, or the canonical legacy/empty prefix for genesis."
    },
    "receipt_hash": {
      "type": "string",
      "pattern": "^sha256:[a-f0-9]{64}$",
      "description": "SHA-256 of the canonical receipt without receipt_hash."
    },
    "kind": {
      "type": "string",
      "pattern": "^[a-z][a-z0-9._-]{1,63}$"
    },
    "subject": {
      "type": "object",
      "description": "Sanitized identity and current operation target.",
      "additionalProperties": true
    },
    "claims": {
      "type": "object",
      "description": "Sanitized claims made by the operation.",
      "additionalProperties": true
    },
    "observations": {
      "type": "object",
      "description": "Sanitized source observations keyed by adapter/kind.",
      "additionalProperties": true
    },
    "recorded_at": {
      "type": "string",
      "format": "date-time"
    }
  }
}