{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://paloframework.org/schemas/palo-external-evidence-ref.schema.json",
  "title": "PALO External Evidence Reference",
  "description": "Immutable, payload-minimized reference to context asserted by an external catalog, observability, identity or source system.",
  "type": "object",
  "required": ["format", "schemaVersion", "evidenceRefId", "tenantId", "subject", "source", "evidenceType", "normalizedClaims", "observedAt", "validUntil", "payloadDigest", "authority", "connector", "status"],
  "properties": {
    "format": { "const": "palo-external-evidence-ref" },
    "schemaVersion": { "const": "1.0.0" },
    "evidenceRefId": { "type": "string", "pattern": "^evidence-ref-[a-f0-9-]{36}$" },
    "tenantId": { "type": "string", "minLength": 1, "maxLength": 128 },
    "subject": { "$ref": "#/$defs/subject" },
    "source": {
      "type": "object",
      "required": ["system", "objectId"],
      "properties": {
        "system": { "type": "string", "minLength": 1, "maxLength": 100 },
        "objectId": { "type": "string", "minLength": 1, "maxLength": 1000 },
        "objectVersion": { "type": "string", "minLength": 1, "maxLength": 500 },
        "uri": { "type": "string", "format": "uri", "maxLength": 2000 }
      },
      "additionalProperties": false
    },
    "evidenceType": { "enum": ["metadata", "lineage", "quality", "classification", "ownership", "access", "data-contract", "audit", "incident", "other"] },
    "normalizedClaims": {
      "type": "object",
      "minProperties": 1,
      "properties": {
        "qualityScore": { "type": "number", "minimum": 0, "maximum": 100 },
        "freshnessAt": { "type": "string", "format": "date-time" },
        "classifications": { "type": "array", "uniqueItems": true, "maxItems": 100, "items": { "type": "string", "minLength": 1, "maxLength": 200 } },
        "owner": { "type": "string", "minLength": 1, "maxLength": 500 },
        "approved": { "type": "boolean" },
        "accessState": { "enum": ["granted", "requested", "denied", "revoked", "unknown"] },
        "lineageComplete": { "type": "boolean" },
        "permittedPurposes": { "type": "array", "uniqueItems": true, "maxItems": 100, "items": { "type": "string", "minLength": 1, "maxLength": 300 } },
        "lifecycleState": { "type": "string", "minLength": 1, "maxLength": 100 },
        "incidentOpen": { "type": "boolean" },
        "contractVersion": { "type": "string", "minLength": 1, "maxLength": 100 },
        "additionalClaimsDigest": { "type": "string", "pattern": "^sha256:[a-f0-9]{64}$" }
      },
      "additionalProperties": false
    },
    "observedAt": { "type": "string", "format": "date-time" },
    "validUntil": { "type": "string", "format": "date-time" },
    "payloadDigest": { "type": "string", "pattern": "^sha256:[a-f0-9]{64}$" },
    "authority": {
      "type": "object",
      "required": ["type", "assertedBy", "verified"],
      "properties": {
        "type": { "enum": ["source-api", "catalog-api", "observability-api", "identity-api", "signed-import", "manual-attestation"] },
        "assertedBy": { "type": "string", "minLength": 1, "maxLength": 500 },
        "verified": { "type": "boolean" }
      },
      "additionalProperties": false
    },
    "connector": {
      "type": "object",
      "required": ["connectorId", "version", "mode", "importedAt"],
      "properties": {
        "connectorId": { "type": "string", "pattern": "^connector-[a-zA-Z0-9][a-zA-Z0-9._-]{2,100}$" },
        "version": { "type": "string", "pattern": "^\\d+\\.\\d+\\.\\d+(?:-[0-9A-Za-z.-]+)?$" },
        "mode": { "const": "read-only" },
        "importedAt": { "type": "string", "format": "date-time" }
      },
      "additionalProperties": false
    },
    "status": { "enum": ["active", "revoked"] }
  },
  "$defs": {
    "subject": {
      "type": "object",
      "required": ["type", "id"],
      "properties": {
        "type": { "enum": ["dataset", "data-product", "model", "ai-system", "agent", "tool", "access-entitlement", "other"] },
        "id": { "type": "string", "minLength": 1, "maxLength": 1000 }
      },
      "additionalProperties": false
    }
  },
  "additionalProperties": false
}