{
  "id": "chatcmpl-sanitized",
  "object": "chat.completion.chunk",
  "model": "reasoning-model",
  "choices": [
    {
      "index": 0,
      "delta": {
        "reasoning": "streamed fallback",
        "reasoning_details": [
          {"type": "reasoning.text", "text": "streamed fallback"}
        ]
      },
      "finish_reason": null
    }
  ]
}