codex - 💡(How to fix) Fix Model Issue [1 comments, 2 participants]

{"type":"error","status":400,"error":{"type":"invalid_request_error","message":"The 'gpt-5.1-codex-mini' model is not supported when using Codex with a ChatGPT account."}} When we select the model gpt-5.1-codex-mini medium and send prompt it produces the error.

TL;DR

The issue can be resolved by removing or disabling the gpt-5.1-codex-mini model from the model selector when using Codex with a ChatGPT account.

Guidance

• Verify that the gpt-5.1-codex-mini model is not supported for ChatGPT accounts by checking the Codex documentation or support resources.
• Check if there are any alternative models available for ChatGPT accounts that can be used instead of gpt-5.1-codex-mini.
• Consider implementing a feature to dynamically update the model selector based on the user's account type to prevent similar issues in the future.
• If the issue persists, try resetting the model selector to its default state or seeking assistance from Codex support.

Notes

The solution assumes that the gpt-5.1-codex-mini model is indeed not supported for ChatGPT accounts. If this is not the case, further investigation may be required to determine the root cause of the issue.

Recommendation

Apply workaround: Remove or disable the gpt-5.1-codex-mini model from the model selector when using Codex with a ChatGPT account, as it is not supported and causes confusion.