{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://meta-universe.org/schemas/2.0/event.schema.json",
  "title": "MUIF Event",
  "description": "An Event: an immutable record of how semantic reality evolves (see 04-core-concepts/Event.md).",
  "type": "object",
  "required": ["muifType", "id", "type", "subject", "occurrenceTime", "provenance"],
  "additionalProperties": false,
  "properties": {
    "muifType": { "const": "Event" },
    "id": { "$ref": "common.schema.json#/$defs/identifier" },
    "type": {
      "type": "string",
      "enum": ["Lifecycle", "Structural", "Semantic", "Disclosure", "Federation", "Conflict"],
      "description": "Event category."
    },
    "subject": { "$ref": "common.schema.json#/$defs/identifier", "description": "Identifier of the affected Object, Relationship, Projection or Contract." },
    "occurrenceTime": { "type": "string", "format": "date-time", "description": "When the change happened in reality. SEMANTIC." },
    "assertionTime": { "type": "string", "format": "date-time", "description": "When the change was recorded. NON-SEMANTIC: excluded from the fingerprint." },
    "payload": { "type": "object", "description": "Semantic content of the change." },
    "causality": {
      "type": "array",
      "description": "Identifiers of the Events or facts that caused this Event (treated as a set).",
      "items": { "$ref": "common.schema.json#/$defs/identifier" }
    },
    "provenance": { "$ref": "common.schema.json#/$defs/provenance" }
  }
}