Is gpt-5 supported?

[drmeister]

I can get the ChatGPT session in emacs to respond when I set the 'chatgpt-model' to "gpt-3.5-turbo" or "gpt-4" but not "gpt-5" or "gpt-5.1". When it doesn't work I get a "400 - Bad request. Please check error message and your parameters".
I don't see any more detailed error messages in Messages or anywhere else.

I am able to use "gpt-5.1" with curl requests:

curl https://api.openai.com/v1/responses -H "Content-Type: application/json" -H "Authorization: Bearer $OPENAI_KEY" -d '{ "model": "gpt-5.1", "input": "Give me a haiku about emacs" }'

...
"output": [
    {
      "id": "msg_0d2dc69dd42506e0006929ae0691e88193913801cd970e9fdf",
      "type": "message",
      "status": "completed",
      "content": [
        {
          "type": "output_text",
          "annotations": [],
          "logprobs": [],
          "text": "Buffers bloom at dawn  \nKey chords weave soft lisping spells  \nText bends to my will"
        }
      ],
      "role": "assistant"
    }
  ],
...