Step 1: Connect GitHub
Authorize Codex to access your GitHub repositories from the ChatGPT interface
Step 2: Describe your task
Write a clear description of what you want Codex to build, fix, or improve
Step 3: Codex works in the background
A cloud sandbox spins up, clones your repo, and Codex executes the task autonomously
Step 4: Receive a pull request
Codex creates a GitHub PR with all changes, a description, and test results for your review
Step 5: Review and merge
Review the changes, request adjustments if needed, and merge when satisfied
Tasks run asynchronously
Unlike a chat conversation where you wait for each response, Codex tasks run in the background. You can close ChatGPT, work on something else, or even start multiple Codex tasks simultaneously. Each task runs in its own container and creates its own pull request when finished. You will receive a notification when each task completes.
Writing effective task descriptions
Codex works best with specific, concrete instructions. Instead of "improve the code," try "Add input validation to the user registration form: validate email format, require password length of at least 8 characters, and show inline error messages." The more specific your description, the closer the result will be to what you want on the first attempt.