{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "urn:orbiplex:schema:execution-receipt:v1",
  "title": "ExecutionReceipt v1",
  "description": "Immutable host-observed transition receipt linking causal context to domain-owned effect and outcome refs.",
  "type": "object",
  "additionalProperties": false,
  "x-dia-workflow": "project",
  "x-dia-status": "draft",
  "x-dia-basis": ["doc/project/40-proposals/081-horizontal-protocol-primitives.md"],
  "required": [
    "schema",
    "schema/v",
    "receipt/id",
    "causal/context",
    "operation/id",
    "capability/id",
    "transition/from",
    "transition/to",
    "attempt/no",
    "recorded/by",
    "recorded/at"
  ],
  "properties": {
    "schema": { "const": "execution-receipt.v1" },
    "schema/v": { "const": 1 },
    "receipt/id": { "type": "string", "pattern": "^execution-receipt:[A-Za-z0-9:_-]+$", "maxLength": 180 },
    "causal/context": { "$ref": "causal-context.v1.schema.json" },
    "operation/id": { "type": "string", "pattern": "^operation:[A-Za-z0-9:_-]+$", "maxLength": 180 },
    "capability/id": { "type": "string", "minLength": 1, "maxLength": 180, "pattern": "^[A-Za-z0-9_.:-]+$" },
    "transition/from": { "$ref": "#/$defs/transition" },
    "transition/to": { "$ref": "#/$defs/transition" },
    "attempt/no": { "type": "integer", "minimum": 1, "maximum": 1000000 },
    "recorded/by": { "$ref": "#/$defs/ref" },
    "recorded/at": { "type": "string", "format": "date-time" },
    "policy/decision-ref": { "$ref": "#/$defs/ref" },
    "effect/refs": {
      "type": "array",
      "maxItems": 16,
      "uniqueItems": true,
      "items": { "$ref": "#/$defs/ref" }
    },
    "outcome/refs": {
      "type": "array",
      "maxItems": 16,
      "uniqueItems": true,
      "items": { "$ref": "#/$defs/ref" }
    },
    "previous/receipt-ref": { "type": "string", "pattern": "^execution-receipt:[A-Za-z0-9:_-]+$", "maxLength": 180 },
    "diagnostics": {
      "type": "object",
      "maxProperties": 16,
      "additionalProperties": { "type": "string", "maxLength": 256 }
    }
  },
  "$defs": {
    "transition": {
      "type": "string",
      "enum": ["proposed", "accepted", "rejected", "deferred", "running", "completed", "failed", "cancelled", "timed-out", "superseded"]
    },
    "ref": { "type": "string", "minLength": 1, "maxLength": 512, "pattern": "^[^\\s]+$" }
  }
}