{
  "id": "msg_abc",
  "type": "message",
  "role": "assistant",
  "model": "claude-sonnet-4-5",
  "content": [
    {
      "type": "text",
      "text": "Hello, world!"
    }
  ],
  "stop_reason": "end_turn",
  "usage": {
    "input_tokens": 123,
    "output_tokens": 45
  }
}