Codex Is Down

Users worldwide are reporting that OpenAI's Codex desktop app is failing with a '404 Not Found' error when trying to reach the backend API at chatgpt.com/backend-api/codex/responses. The issue, filed on GitHub, has drawn dozens of comments from users across the globe, including those on Pro and Plus plans, and appears to affect long-running sessions, often after compactions or when orchestrating sub-agents. Some users report the error recurs after retries, while others note it can be temporarily resolved by sending 'Continue'. The problem seems intermittent and not tied to a specific model, as some sessions with GPT-5.5 remain unaffected.