{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://adcontextprotocol.org/schemas/3.3.0-beta.1/core/identifier.json",
  "title": "Identifier",
  "description": "A property identifier with type and value. Used to identify properties across platforms (domains, app store IDs, etc.).",
  "type": "object",
  "properties": {
    "type": {
      "$ref": "https://adcontextprotocol.org/schemas/3.3.0-beta.1/enums/identifier-types.json",
      "description": "Type of identifier"
    },
    "value": {
      "type": "string",
      "description": "The identifier value. Domain and subdomain values MUST be lowercase ASCII hostnames (IDNs use lowercase A-label/punycode form), without scheme, path, port, whitespace, or trailing dot. Domain permits one leading '*.'; subdomain does not. For domain: 'example.com' matches base plus www and m; 'edition.example.com' matches that subdomain; '*.example.com' matches all subdomains but not the base. Invalid values MUST cause rejection of the containing request; receivers MUST NOT silently discard identifiers."
    }
  },
  "required": [
    "type",
    "value"
  ],
  "additionalProperties": false,
  "allOf": [
    {
      "if": {
        "properties": {
          "type": {
            "const": "domain"
          }
        },
        "required": [
          "type"
        ]
      },
      "then": {
        "properties": {
          "value": {
            "pattern": "^(?:\\*\\.)?[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?(?:\\.[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?)+$(?![\\s\\S])",
            "maxLength": 255,
            "allOf": [
              {
                "if": {
                  "pattern": "^\\*\\."
                },
                "else": {
                  "maxLength": 253
                }
              }
            ]
          }
        }
      }
    },
    {
      "if": {
        "properties": {
          "type": {
            "const": "subdomain"
          }
        },
        "required": [
          "type"
        ]
      },
      "then": {
        "properties": {
          "value": {
            "pattern": "^[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?(?:\\.[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?)+$(?![\\s\\S])",
            "maxLength": 253
          }
        }
      }
    }
  ]
}