{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://receiptprotocol.com/open-receipt/v0.2/event.schema.json",
  "title": "Open Receipt event v0.2",
  "type": "object",
  "additionalProperties": false,
  "required": [
    "spec_version",
    "event_id",
    "event_type",
    "issuer",
    "issued_at",
    "transaction_id",
    "quote_id",
    "commercial_facts",
    "evidence",
    "provenance",
    "assurance",
    "parent_event_hashes",
    "signing_key_id",
    "issuer_metadata_version",
    "issuer_metadata_hash",
    "signature"
  ],
  "properties": {
    "spec_version": { "const": "0.2" },
    "event_id": { "type": "string", "minLength": 1 },
    "event_type": {
      "enum": [
        "quote.issued",
        "authorization.granted",
        "execution.attempted",
        "validation.completed",
        "settlement.completed",
        "reversal.issued"
      ]
    },
    "issuer": { "$ref": "event.schema.json#/$defs/issuer" },
    "issued_at": { "type": "string", "format": "date-time" },
    "transaction_id": { "type": "string", "minLength": 1 },
    "quote_id": { "type": ["string", "null"] },
    "commercial_facts": { "type": "object", "additionalProperties": true },
    "evidence": { "type": "object", "additionalProperties": true },
    "provenance": { "type": "object", "additionalProperties": true },
    "assurance": { "enum": ["delivered", "validated"] },
    "parent_event_hashes": {
      "type": "array",
      "items": {
        "type": "string",
        "pattern": "^(?:sha256:)?[a-f0-9]{64}$",
        "description": "SHA-256 reference. New events use the sha256: prefix; bare digests remain accepted for immutable early-v0.2 events."
      },
      "uniqueItems": true
    },
    "signing_key_id": { "type": "string", "minLength": 1 },
    "issuer_metadata_version": { "type": "integer", "minimum": 1 },
    "issuer_metadata_hash": { "type": "string", "pattern": "^sha256:[a-f0-9]{64}$" },
    "issuance_attestation": { "$ref": "issuance-attestation.schema.json" },
    "signature": {
      "type": "string",
      "pattern": "^[A-Za-z0-9_-]+\\.\\.[A-Za-z0-9_-]+$"
    }
  }
}