Codex is OpenAI's software engineering agent. It takes on bugs, refactors and new features, runs many agents in parallel, and checks its own work with computer and browser tools until the requirements are met.

Key features:

Run multiple agents in parallel and steer or review them in one place.
Verify changes using computer and browser tools.
Keep tasks running in the cloud with reusable environments for every repository.
Review pull requests automatically, surfacing findings and answering questions.
Connect other tools and add capabilities with plugins.
Use the same agent in the ChatGPT app, on the web, in an IDE extension or in the CLI.

The Codex CLI installs with npm, and all surfaces share a ChatGPT account. Codex is included in ChatGPT plans: Plus at $20/month, Pro at $100/month for higher limits, and Business at $20 per user per month (2+ seats, billed annually) with a shared workspace and admin controls.