Support for GPT-5-Codex

[luispl77]

Describe the feature or problem you'd like to solve

The normal GPT-5 model is not optimized for programming and makes several mistakes.

Proposed solution

Could you please add support for GPT-5-Codex?

Here is a resource by OpenAI on migrating to GPT-5-Codex, prompts and tools:

https://cookbook.openai.com/examples/gpt-5-codex_prompting_guide

Thank you

Example prompts or workflows

No response

Additional context

No response

[csvan]

Should be noted that Codex is available as a preview model in vscode copilot, so hopefully this CLI can jump on the same integration

[halimsamy]

+1

[rishitank]

+1, following this thread

[joshlacal]

Would absolutely love to see 5-Codex in CLI, seems like the perfect fit

[jlliu-sequoia]

+1 Would absolutely love to see 5-Codex in CLI

[uyrabi]

+1 Lately, an acquaintance of mine is absolutely obsessed with gpt-5-codex.
I can't wait to use it quickly with copilot cli.

[cwbrandsdal]

When can we expect this?

[luispl77]

@RyanHecht Hello, sorry to bother, but it's been really a long time since I first mentioned this issue with GPT-5-Codex missing.

Really would be great if you could do this. I am liking using Github CLI lately but unfortunately Claude Sonnet 4.5 is very expensive and I quickly run out of usage, would be great if you could offer GPT-5-codex at a lower cost too.

Thanks!

[csvan]

Codex and Claude 4.5 have the same credit cost in Copilot

[RyanHecht]

We'll do you one better (well, 0.1 better) -- GPT-5.1-Codex is now available (at 1x), as well as GPT-5.1-Codex-Mini (at 0.33x)!

https://github.com/github/copilot-cli/releases/tag/v0.0.356

[Inrego]

@RyanHecht I don't see either 5.1 models in Copilot CLI version 0.0.357
I have enabled the model and can use it in CoPilot in Rider.

 ✗ Model "GPT-5.1-Codex" is not supported by Copilot CLI.

   Supported models:
     - "claude-sonnet-4.5"
     - "claude-sonnet-4"
     - "claude-haiku-4.5"
     - "gpt-5"

[TheLoloS]

@RyanHecht I don't see either 5.1 models in Copilot CLI version 0.0.357 I have enabled the model and can use it in CoPilot in Rider.

 ✗ Model "GPT-5.1-Codex" is not supported by Copilot CLI.

   Supported models:
     - "claude-sonnet-4.5"
     - "claude-sonnet-4"
     - "claude-haiku-4.5"
     - "gpt-5"

They broke something or removed it in 0.0.357. Downgrade to 0.0.356 and it should work again.