### 1 · SendMessage: a question
POST /a2a/jsonrpc HTTP/1.1
Host: localhost:41242
Content-Type: application/json
A2A-Version: 1.0

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "SendMessage",
  "params": {
    "message": {
      "messageId": "d95bafc8-f2a4-427b-9cf4-bb99f4bea973",
      "role": "ROLE_USER",
      "parts": [
        {
          "text": "What languages can you review?"
        }
      ]
    }
  }
}

HTTP/1.1 200 OK
Content-Type: application/json

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "message": {
      "messageId": "3b4b1206-4b6f-467f-b735-2d7e4f7f4bcd",
      "contextId": "dc423c62-d5f4-48e5-82c0-4963b9bc4334",
      "role": "ROLE_AGENT",
      "parts": [
        {
          "text": "I review unified diffs in Python, TypeScript and Go. Send the diff as a text/x-diff part and name the base branch."
        }
      ]
    }
  }
}