Codex Is Down

OpenAI's Codex desktop app (version 26.611.61753) is failing for some Pro subscribers with repeated 'unexpected status 404 Not Found' errors from the chatgpt.com backend, interrupting long-running sessions. A user on a GPT-5.4 xhigh session reported the error three times in a row, while a separate GPT-5.5 xhigh session remained unaffected, and the issue persisted after retries. The user suggests more resilient retry logic with exponential backoff to prevent mid-session failures.

- Notifications /login?return to=%2Fopenai%2Fcodex You must be signed in to change notification settings - Fork 18.6k /login?return to=%2Fopenai%2Fcodex unexpected status 404 Not Found: Unknown error, url: https://chatgpt.com/backend-api/codex/responses, cf-ray: ... 28756 appIssues related to the Codex desktop app https://github.com/openai/codex/issues?q=state%3Aopen%20label%3A%22app%22 Issues related to the Codex desktop app bugSomething isn't working https://github.com/openai/codex/issues?q=state%3Aopen%20label%3A%22bug%22 Something isn't working connectivityIssues involving networking or endpoint connectivity problems disconnections https://github.com/openai/codex/issues?q=state%3Aopen%20label%3A%22connectivity%22 Issues involving networking or endpoint connectivity problems disconnections sessionIssues involving session thread management, resuming, forking, naming, archiving https://github.com/openai/codex/issues?q=state%3Aopen%20label%3A%22session%22 Issues involving session thread management, resuming, forking, naming, archiving Description EDIT: To everyone here, the solution was actually reasonably simple, just follow these instructions https://www.youtube.com/watch?v=dQw4w9WgXcQ&list=RDdQw4w9WgXcQ . What version of the Codex App are you using From “About Codex” dialog ? 26.611.61753 What subscription do you have? Pro x20 What platform is your computer? Darwin 25.3.0 arm64 arm What issue are you seeing? Repeatedly encountering in my GPT 5.4 xhigh session: unexpected status 404 Not Found: Unknown error, url: https://chatgpt.com/backend-api/codex/responses, cf-ray: ... I can send a message and get an update back, but then when the agent would think and continue I encountered this error 3 times in a row. I have another session running with GPT 5.5 xhigh and it seems to be unaffected. What steps can reproduce the bug? I have a long running session going, it's had many compactions and plenty of steering. I've also been spinning up sub-agents for smaller tasks where this session is acting as an orchestrator. It failed shortly after steering it to spin up a sub-agent, not sure if that's related. Session stopped with this error, it retried 5/5 times and gave up. This did not occur immediately after compaction, but it was shortly there after, maybe around 50k tokens. Sending Continue did work, but it failed again after taking a turn. I tried this twice more and it does seem that for now the session is continuing on. What is the expected behavior? Don't die mid session. Ideally we'd also have more error resistant retries with exponential back-off to something like 20 retries over 10 minutes. Additional information No response Activity Metadata Metadata Assignees Labels appIssues related to the Codex desktop app https://github.com/openai/codex/issues?q=state%3Aopen%20label%3A%22app%22 Issues related to the Codex desktop app bugSomething isn't working https://github.com/openai/codex/issues?q=state%3Aopen%20label%3A%22bug%22 Something isn't working connectivityIssues involving networking or endpoint connectivity problems disconnections https://github.com/openai/codex/issues?q=state%3Aopen%20label%3A%22connectivity%22 Issues involving networking or endpoint connectivity problems disconnections sessionIssues involving session thread management, resuming, forking, naming, archiving https://github.com/openai/codex/issues?q=state%3Aopen%20label%3A%22session%22 Issues involving session thread management, resuming, forking, naming, archiving