Codex for Claude Code

Two assistants built by different companies rarely make the same mistake, and the one that wrote the code is the worst judge of it. This is OpenAI's own add-on for Claude Code. It calls in Codex, their coding assistant, to read the changes just made and report what it finds, without you switching apps. The other half is handing work over rather than checking it: Codex takes the job, runs in the background, and reports back when it is done. The plugin itself is free; the work runs against your ChatGPT account's Codex allowance, which a free account gets a small amount of, and the image making it can also do needs a paid OpenAI account.

Straight after a change big enough that you would want someone else to look at it, or on a stubborn bug where a fresh opinion beats another attempt. Handing work over is the other half. Because Codex can write and run code of its own, a job you pass to it can go well beyond code: it can even produce finished images for you (needs a paid OpenAI account). There is no button for it, you simply ask.

1. Type the command below inside Claude Code. It adds OpenAI's catalogue.
2. Install it by typing /plugin install codex@openai-codex, then /reload-plugins
3. Type /codex:setup once. It checks Codex is ready and offers to fetch it if not. After that, /codex:review looks over your current work.