gpt-6-astra falls back to OPENAI_API_KEY for image generation

What version of Codex CLI is running?

latest

What subscription do you have?

API

Which model were you using?

gpt-6-astra

What platform is your computer?

mac

What terminal emulator and version are you using (if applicable)?

No response

Codex doctor report

What issue are you seeing?

not entirely sure what the problem is, i dont see any error logs. im using litellm with codex and it wants to fallback to OPENAI_API_KEY for using the image generation tool. i can confirm that litellm does support the image generation tool and can generate images with astra, but its not clear if codex has that tool available in the session

What steps can reproduce the bug?

• configure litellm proxy in your ~/.codex/config.toml
• start a new codex session with astra
• ask it to generate a logo or a png

What is the expected behavior?

it should use the image gen api with litellm to generate images, and not fall back to the openai api key

Additional information

No response

Start by reproducing the issue with LiteLLM configured in ~/.codex/config.toml, a new Codex session using gpt-6-astra, and an image-generation request. Trace how the image generation tool selects its API credentials and verify that the completed behavior routes through LiteLLM without falling back to OPENAI_API_KEY.