model_reasoning_effort is Not Supported in gpt-5.1-codex
Resolved 💬 4 comments Opened Nov 14, 2025 by gaoconggit Closed Nov 16, 2025
💡 Likely answer: A maintainer (etraut-openai, contributor)
responded on this thread — see the highlighted reply below.
What version of Codex is running?
0.58.0
What subscription do you have?
chatGPT Pro
Which model were you using?
gpt-5.1-codex
What platform is your computer?
win11
What issue are you seeing?
unexpected status 400 Bad Request: {
"error": {
"message": "Unsupported value: 'none' is not supported with the 'gpt-5.1-codex' model. Supported values are: 'low', 'medium', and 'high'.",
"type": "invalid_request_error",
"param": "reasoning.effort",
"code": "unsupported_value"
}
}
What steps can reproduce the bug?
<img width="1037" height="543" alt="Image" src="https://github.com/user-attachments/assets/cd0ab515-d80e-44b2-80eb-8987f8db3464" />
What is the expected behavior?
_No response_
Additional information
_No response_
4 Comments
GPT-5.1 works fine.
Are you setting the reasoning effort to
none?Yeah, I already did that.
'none' is not supported with the 'gpt-5.1-codex' model. Supported values are: 'low', 'medium', and 'high'