{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://artifact-chain.dev/schemas/project-facts.schema.json",
  "title": "Project Facts Evidence Envelope",
  "description": "Structured envelope capturing project identity, configuration, graph state, and evidence for registry/planner consumption",
  "type": "object",
  "required": ["schemaVersion", "projectRoot", "configDigest", "artifactGraphSummary", "targetArtifact", "contractRevisionDigest", "proofStatus", "versionLockStatus", "sourcesFreshness", "bindingFreshness", "evidenceDigest"],
  "additionalProperties": false,
  "properties": {
    "schemaVersion": {
      "type": "integer",
      "const": 1
    },
    "projectRoot": {
      "type": "string",
      "minLength": 1,
      "description": "Project root identity (path or canonical identifier)"
    },
    "configDigest": {
      "type": "string",
      "pattern": "^sha256:[a-f0-9]{64}$",
      "description": "SHA-256 digest of artifact-graph.config.yaml content"
    },
    "policyDigest": {
      "type": ["string", "null"],
      "pattern": "^sha256:[a-f0-9]{64}$",
      "description": "SHA-256 digest of project policy overlay, or null if none"
    },
    "artifactGraphSummary": {
      "type": "object",
      "required": ["artifactCount", "edgeCount", "contextTargets"],
      "additionalProperties": false,
      "properties": {
        "artifactCount": { "type": "integer", "minimum": 0 },
        "edgeCount": { "type": "integer", "minimum": 0 },
        "contextTargets": {
          "type": "array",
          "items": { "type": "string" }
        }
      }
    },
    "targetArtifact": {
      "type": "object",
      "required": ["type", "id"],
      "additionalProperties": false,
      "properties": {
        "type": { "type": "string", "minLength": 1 },
        "id": { "type": "string", "minLength": 1 }
      }
    },
    "contractRevisionDigest": {
      "type": "string",
      "pattern": "^sha256:[a-f0-9]{64}$",
      "description": "SHA-256 digest of the contract revision content"
    },
    "proofStatus": {
      "type": "string",
      "enum": ["present", "missing", "stale"]
    },
    "versionLockStatus": {
      "type": "string",
      "enum": ["fresh", "stale", "missing"]
    },
    "sourcesFreshness": {
      "type": "string",
      "enum": ["fresh", "stale", "missing"],
      "description": "Freshness of the adopted catalog source set"
    },
    "bindingFreshness": {
      "type": "string",
      "enum": ["fresh", "stale", "missing"],
      "description": "Freshness of the project provider binding"
    },
    "evidenceDigest": {
      "type": "string",
      "pattern": "^sha256:[a-f0-9]{64}$",
      "description": "SHA-256 digest of the envelope content excluding this field, using stable key serialization"
    }
  }
}