Common Codex Issues

Codex remembers who you are after the first sign-in. That is convenient until you switch accounts or plans, your session ends, or a sign-in attempt fails halfway and leaves things in a confusing state. Codex then asks you to sign in again, keeps using the wrong account, or fails every time.

You sign in to Codex in the terminal, the editor extension or the desktop app. The browser says you are signed in, and then Codex shows token exchange failed: error sending request for url (https://auth.openai.com/oauth/token).

The browser step worked. What failed is the next one: Codex itself could not reach OpenAI's sign-in server to finish the login. That points to something between your computer and the internet, not to your account.

Codex finished a task and opened a pull request. GitHub shows This branch has conflicts that must be resolved and the merge button is disabled.

It means the same lines were changed in two places: by Codex on its branch, and by someone (maybe you) on the main branch since Codex started.

The app Codex built runs fine on your computer. After you put it online, the page is blank, a feature fails, or the host reports a failed build.

The code is the same in both places. What differs is everything around it: settings, versions, the database and how the app is started.

You installed the Codex command line tool, but typing codex in the terminal gives command not found (or 'codex' is not recognized on Windows).

Most of the time the install worked. The terminal just does not know where the program was put.

You start your app and it fails with Error: listen EADDRINUSE: address already in use :::3000 (or another port number, such as 5173 or 8080).

Something is already using that port. After an AI coding tool has run your project, that is often a copy of your own app that it started and never stopped.

You asked Codex for one change. It edited several files, and now the app shows an error, a blank page, or won't build at all. You cannot tell which of the changes caused it.

You paste the error. Codex makes a change and says it is fixed. The error comes back, and the next attempt is almost the same change. After a few rounds you have a messier project and the same problem.

Codex can build an app that works when you click through it yourself. That does not mean it is safe for strangers. The problems that matter most do not show up in a quick test: a key in the wrong place, a page anyone can open, or a database anyone can read.

Codex reports that all tests pass. You open the app, follow the steps a real user would, and the feature fails.