Codex
OpenAI's cloud-based coding agent that writes features, fixes bugs, and creates pull requests while running in isolated sandbox environments.
What is Codex?
Codex is OpenAI's cloud-based software engineering agent that handles complete coding tasks from start to finish.
It runs each task in its own sandbox environment preloaded with your repo, where it can write code, run tests, fix bugs, and propose pull requests for review.
Powered by codex-1 (a version of o3 trained on real-world coding tasks), it works through ChatGPT's sidebar or the new Codex desktop app. You assign it tasks, it works independently for 1-30 minutes, and you review the changes before merging.
Available to ChatGPT Pro, Business, and Enterprise users now, with Plus access rolling out soon. The desktop app for macOS lets you run multiple agents in parallel across different projects.
Good to Know
Runs tasks in isolated sandbox environments preloaded with your codebase
Powered by codex-1, a version of o3 fine-tuned on real-world development workflows
Can write features, run tests, fix bugs, and propose pull requests independently
Tasks typically take 1-30 minutes and you can monitor progress in real time
Available through ChatGPT sidebar and new macOS desktop app for managing multiple agents
How Vibe Coders Use Codex
Assigning it a feature request and reviewing the PR it generates an hour later
Asking it to explain a complex function in your codebase with context from surrounding files
Running multiple agents in parallel across different repos while you focus on architecture
Giving it a bug report and letting it iterate on fixes until tests pass
Frequently Asked Questions
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