Use Codex in GitHub

Use Codex to review pull requests without leaving GitHub. Add a pull request comment with @codex review, and Codex replies with a standard GitHub code review.

Set up code review

1. Set up Codex cloud.
2. Go to Codex settings and turn on Code review for your repository.

Request a review

1. In a pull request comment, mention @codex review.
2. Wait for Codex to react (👀) and post a review.

Codex posts a review on the pull request, just like a teammate would.

Enable automatic reviews

If you want Codex to review every pull request automatically, turn on Automatic reviews in Codex settings. Codex will post a review whenever a new PR is opened for review, without needing an @codex review comment.

Customize what Codex reviews

Codex searches your repository for AGENTS.md files and follows any Review guidelines you include.

To set guidelines for a repository, add or update a top-level AGENTS.md with a section like this:

## Review guidelines

- Don't log PII.
- Verify that authentication middleware wraps every route.

Codex applies guidance from the closest AGENTS.md to each changed file. You can place more specific instructions deeper in the tree when particular packages need extra scrutiny.

For a one-off focus, add it to your pull request comment, for example:

@codex review for security regressions

In GitHub, Codex flags only P0 and P1 issues. If you want Codex to flag typos in documentation, add guidance in AGENTS.md (for example, “Treat typos in docs as P1.”).

Give Codex other tasks

If you mention @codex in a comment with anything other than review, Codex starts a cloud task using your pull request as context.

@codex fix the CI failures