GPT 5.3 Codex Copilot

[ADYADY222]

Description

I'm trying to use the GPT 5.3 Codex model from Github and it says The requested model is not supported

Plugins

Opencode Extension V0.0.13

OpenCode version

1.1.60

Steps to reproduce

I selected GPT 5.3 Codex from /models and when I tried to send a message to see if it worked, it gave me the error The requested model is not supported, after which I logged out (opencode auth logout/login) and then logged in but it still did the same thing, including when I entered a new session it still said The requested model is not supported

Screenshot and/or share link

Operating System

Windows 11

Terminal

Opencode CLI/Terminal

[github-actions]

This issue doesn't fully meet our contributing guidelines.

What needs to be fixed:

• Steps to reproduce: Required for bug reports but shows "No response" - please describe what you did when you encountered this error
• Operating System: Required context to help debug model compatibility issues
• Terminal: Required for context
• Plugins: Please specify what plugins you have installed

Please edit this issue to address the above within 2 hours, or it will be automatically closed.

---

Potential duplicates found: This issue might be related to existing GitHub Copilot + GPT-5.3-Codex support issues:

• The requested model is not supported. #12789: "The requested model is not supported." with GitHub Copilot
• The requested model is not supported. Make sure the model is enabled in your copilot settings: https://github.com/settings/copilot/features #11473: Same error with Copilot settings context
• gpt-5.3-codex fails with 404 when authenticated via OpenAI API key #12839: "gpt-5.3-codex fails with 404 when authenticated via OpenAI API key"
• Responses using GPT-5.3-Codex (from OpenAI Codex) terminate early #12570: "Responses using GPT-5.3-Codex (from OpenAI Codex) terminate early"

Please check these issues to see if they describe your problem, as this might be a known limitation rather than a new bug.

If you believe this was flagged incorrectly, please let a maintainer know.

[muhammadsyaddad]

i think the error is form the github itself not the opencode "code" , i put session log where i use gpt-5.3-codex model its return
""""
{"error":{"message":"The requested model is not supported.","code":"model_not_supported","param":"model","type":"invalid_request_error"}}
""""

ex.log

[muhammadsyaddad]

and also i found this
https://github.com/orgs/community/discussions/186787

[JReis23]

and also i found this https://github.com/orgs/community/discussions/186787

I don't think this is the problem. I'm not able to use Codex 5.3 in opencode, but with the IDE (zed in my case) I can use it.

[YuldShah]

same issue here.

[github-actions]

This issue has been automatically closed because it was not updated to meet our contributing guidelines within the 2-hour window.

Feel free to open a new issue that follows our issue templates.