{
  "$id": "https://oaslananka.github.io/a2amesh/schemas/message.schema.json",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "additionalProperties": false,
  "description": "Agent2Agent message payloads accepted by A2A Mesh.",
  "properties": {
    "contextId": { "type": "string" },
    "kind": { "const": "message", "type": "string" },
    "messageId": { "type": "string" },
    "parts": {
      "items": {
        "oneOf": [
          {
            "additionalProperties": false,
            "properties": {
              "text": { "type": "string" },
              "type": { "const": "text", "type": "string" }
            },
            "required": ["type", "text"],
            "type": "object"
          },
          {
            "additionalProperties": false,
            "properties": {
              "file": {
                "additionalProperties": false,
                "properties": {
                  "bytes": { "type": "string" },
                  "mimeType": { "type": "string" },
                  "name": { "type": "string" },
                  "uri": { "type": "string" }
                },
                "required": ["mimeType"],
                "type": "object"
              },
              "type": { "const": "file", "type": "string" }
            },
            "required": ["type", "file"],
            "type": "object"
          },
          {
            "additionalProperties": false,
            "properties": {
              "data": {
                "additionalProperties": {},
                "propertyNames": { "type": "string" },
                "type": "object"
              },
              "type": { "const": "data", "type": "string" }
            },
            "required": ["type", "data"],
            "type": "object"
          }
        ]
      },
      "type": "array"
    },
    "role": { "enum": ["ROLE_USER", "ROLE_AGENT"], "type": "string" },
    "timestamp": {
      "format": "date-time",
      "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$",
      "type": "string"
    }
  },
  "required": ["role", "parts", "messageId", "timestamp"],
  "title": "A2A Mesh Message",
  "type": "object",
  "x-a2a-source": {
    "schemaSymbol": "MessageSchema",
    "sourceFile": "packages/runtime/src/types/task.ts",
    "typeSymbol": "Message"
  }
}