Issue using VS CODE and connecting to Codex: unexpected status 404 Not Found auth error: 404
OpenAI Developer Community
May 15, 2026
I am encountering the error:
unexpected status 404 Not Found: Unknown error, url: https ://chatgpt. com/backend-api/codex/responses, cf-ray: 9fc45f2c0cd06e1b-YVR, request id: 6e358a55-d0c1-44c8-ad9c-64fd266f9fa0, auth error: 404
The issue was only occurring for one window, but run multiple windows at once on multiple projects. I never had an issue for the past 40 days until today. I tried to clear my cache, sign out, restart the application, reinstall the extension. All the possible steps I have tried did not work.
I also noticed my usage has exponentially shortened for this week, while last week I was able to use it continuously for 6 days, even exhausting my codex-spark usage during that period.
In only 39 hours, i’ve used 48% of my usage compared to last week, when I started to see usage drain exponentially once I used 30% of my usage. At 70% the drain became quite noticeable.
When I was left with 3%, the usage seems to slow.
This week, usage is draining faster than ever. I noticed claude pro has slightly increased the usage, but you still face constraints in the 5 hour window compared to the doubling and usage of your weekly quota.
Codex is still generous but the change in how it functions does not seem appropriate. I do like that ChatGPT pro request is not limited to the degree that it was last week.
Back to my issue, why am I facing a connection error after trying to troubleshoot the problem from all possible angles?
Discussion in the ATmosphere