Production systems
For the complete documentation index, see llms.txt. Markdown versions of documentation pages are available by appending
.mdto the page URL.
Navigate, refactor, and review real codebases.
The use cases in this collection are useful when Codex is working in a repo that already has history, tests, owners, and production constraints. Codex is particularly good at navigating complex codebases, including sprawling monorepos with lots of different services and dependencies. If you're working on a production system, get familiar with these use cases to understand how Codex can help you.
Start with a codebase tour
Use Codex to get familiar with a complex codebase, which is especially useful when onboarding onto a repo for production software.
- Understand large codebases: Use Codex to map unfamiliar codebases, explain different modules and data flow, and point...
Modernize the codebase
Leverage Codex to plan tech stack migrations, upgrade your integration to the latest models if applicable, and refactor the codebase to improve readability and maintainability.
- Upgrade your API integration: Use Codex to update your existing OpenAI API integration to the latest recommended models...
- Refactor your codebase: Use Codex to remove dead code, untangle large files, collapse duplicated logic, and...
- Run code migrations: Use Codex to map a legacy system to a new stack, land the move in milestones, and validate...
Codify repeatable work
Ask Codex to turn repo-specific workflows or checklists into a skill, so that all repo contributors can benefit from a standardized process.
- Save workflows as skills: Turn a working Codex chat, review rules, test commands, release checklists, design...
Keep documentation current
Ask Codex to compare source changes with existing docs, update the smallest useful docs surface, and verify the changes.
- Keep documentation up-to-date: Use Codex to compare source code changes, public docs, release notes, and PR context, then...
Maintain system health
Let Codex pick up feature requests and bug fixes automatically by using it from Slack and connecting it to your alerting, issue tracking, and daily bug sweeps.
- Kick off coding tasks from Slack: Mention
@Codexin Slack to start a chat tied to the right repo and environment, then... - Automate bug triage: Ask Codex to check recent alerts, issues, failed checks, logs, and chat reports, tune the...
Avoid the review bottleneck
Use Codex to automatically review PRs and run focused QA passes on critical flows, so you can catch issues quickly and ship updates confidently.
- Review GitHub pull requests: Use Codex code review in GitHub to automatically surface regressions, missing tests, and...
- QA your app with Computer Use: Use Computer Use to exercise key flows, catch issues, and finish with a bug report.