The same request, but it returns a task_id immediately and generates in the background. Retrieve with GET /api/v1/tasks/{id} -- the same endpoint the video tasks use, rendered according to the task's modality.

X-DashScope-Async: enable is accepted and ignored: this endpoint is always asynchronous, and omitting the header is not an error.

Note that parameters are still validated at submit time. The vendor's own asynchronous endpoint does not validate them (a bad size is accepted and the task fails ten-odd seconds later); Amux rejects before the task is created, naming the parameter and the accepted range.

{
  "model": "alibaba/qwen-image-3.0",
  "input": {
    "messages": [
      {
        "role": "user",
        "content": [
          {
            "text": "A red paper boat drifting down a rain gutter"
          }
        ]
      }
    ]
  },
  "parameters": {
    "size": "1024*1024"
  }
}