Agents in Xcode: Codex Sign In not working

any solution. im having the same problem today.

Thank you for your post. Are you encountering the issue with the RC 26.5?

I think I have seen that issue with previous version where the tokens getting stuck in your Keychain.

Ensure you are actively connected without VPN or proxies. As requires a stable connection to internal services to validate the token. If your network connection dropped briefly during the auth handoff, it will fail silently and leave you in the "Not Signed In" state.

Also can you delete any cache? In your terminal:

rm -rf ~/Library/Caches/com.apple.dt.Xcode

If the issue persists please let me know and we can file a bug to see the issue in Xcode 25.6 RC.

Albert
  Worldwide Developer Relations.

Hey Albert,

thanks for your competent reply.

Yes, Xcode release candidate 26.5 (17F42).

I have deleted the cache. I have also deleted codex* and chatgpt* (empty) from the system keychain. No VPN connection. The problem persists.

I have now switched Xcode over to use "Authenticate with configuration file". It does that, but I am unsure whether the configuration file works, and I don't really know how to check. The codex* entries in keychain are back since I logged in on the Codex app.

Kind regards

i have the same error. let me know if you find a fix

Thank you for providing additional information. I believe that multiple developers experiencing the same issue suggests that it is not solely a configuration problem and should be investigated by the appropriate team.

May I request that you file a bug so that I can route it correctly to that team?

Once you open the bug report, please post the FB number here for my reference.

If you have any questions about filing a bug report, take a look at Bug Reporting: How and Why?

Albert
  Worldwide Developer Relations.

I filed Feedback a couple of days ago:

FB22732574

I have installed the new Xcode 26.5 release version (and I am on macOS 26.5).

It works now!

Maybe someone can confirm.

@otacon85 Thank you for providing the updated information in the thread. I noticed that you did not post this information in the bug thread. I recommend that you update the FB22732574 with the exact same information you just posted so that the team can verify it for you.

Thank you.

Albert
  Worldwide Developer Relations.

Getting the same issue, updated to MacOS 26.5 to try to fix it, but once Xcode auto-updated to 26.5, codex was unable to send prompts. I signed out to try and fix it, but then I couldn't sign back in. I tried clearing the cache, signing in and out of ChatGPT on Xcode, restarting multiple times and there is just no way to authenticate.

It perpetually says 'Not Signed in', despite the auth pop-up on Safari window authenticating successfully, and going back to localhost "you can close this window now".

Tested Claude agent signing in and out, as well as ChatGPT (Chat) in Xcode and they both work no problem. Was working in 26.4, no problem, without restarting the auto-update broke codex functionality. After Mac restart & update from MacOS 26.4 to 26.5, still broken (as well as updating Xcode CLI tools).

Think this is a glitch on Xcode side. This seems like the inverse to the thread's problem for me -- Codex working fine in Xcode version 26.4, but broken once updated to version 26.5

@jezza- Thanks for the great description. Would you be so kind to file a bug with that configuration and provide the sysdiagnose to see why isn't working for you?

If you have any questions about filing a bug report, take a look at Bug Reporting: How and Why?

Albert
  Worldwide Developer Relations.