Codex is OpenAI’s coding agent, available in ChatGPT, an editor extension, a CLI and the cloud.

Does it work while I am away?

OpenAI says Codex keeps going when you close your laptop, using cloud environments you can return to from another device.

OpenAI says it automatically reviews pull requests, surfaces findings and answers questions.

Can I trust its changes?

Treat them like a colleague’s pull request: read the diff and run the tests before merging.

OpenAI

Codex

Codex is OpenAI’s coding agent. Its own page says it works across ChatGPT, your editor and the terminal, runs agents in parallel, keeps tasks going in the cloud, and reviews pull requests.

Open Codex ↗Watch and learn Common questions

What Codex does

Takes engineering tasks such as hard-to-find bugs, complex refactors and new features.
Runs many agents in parallel, using computer and browser tools to verify work.
Keeps tasks going in reusable cloud environments for each repo, so you can pick up from another device.
Reviews pull requests automatically, surfaces findings and answers questions.
Works in ChatGPT, an IDE extension and a CLI, and connects tools through plugins.

What people use it for

Chase a bug
Hand Codex a hard-to-reproduce bug and review the change it proposes.
Review pull requests
Use its automatic review as a first pass before a person reviews.
Start in the cloud
Start a task, close your laptop and check the result later.

Who it suits

Software engineers and teams who want an agent working across repos.
Teams that want automated review as a first pass.

Plans and access

OpenAI says Codex is included in your ChatGPT plan, and lists Plus, Pro and Business plans. Plans and limits change, so read OpenAI’s current terms. Review every change before you merge it, and give the agent only the repository access it needs.

How to start

1Open the Codex page and sign in with ChatGPT. Open
2Try it on a small, well-tested part of a repo first.
3Read the diff and run the tests yourself before you accept a change.
4Add automatic pull request review once you trust how it behaves.

Watch and learn

Videos from OpenAI’s own channel, so you can learn it here. Nothing loads from YouTube until you press play. More on the OpenAI channel.

OpenAI · 2026
Meet the all new Codex Cloud
Open on YouTube
OpenAI · 2026
Meet the New Codex CLI
Open on YouTube
OpenAI · 2026
Code review is no longer the bottleneck
Open on YouTube

Keep learning on Infrato

Course: AI-Assisted Coding You Can Trust
Path: AI for software developers
Directory: 16 courses from OpenAI
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Common questions about Codex

What is Codex?: Codex is OpenAI’s coding agent, available in ChatGPT, an editor extension, a CLI and the cloud.
Does it work while I am away?: OpenAI says Codex keeps going when you close your laptop, using cloud environments you can return to from another device.
Does it review code?: OpenAI says it automatically reviews pull requests, surfaces findings and answers questions.
Can I trust its changes?: Treat them like a colleague’s pull request: read the diff and run the tests before merging.

Where this comes from

Written from the maker’s own pages, read on 2026-10-13. Plans, limits and features change, so the page you land on is the source.

Each tool links to its maker’s own page. They are listed so you know what exists and what to learn, not ranked, and they are not endorsements. We are not affiliated with these companies. A tool can change or be renamed; the page you land on is the source.