Cloud-based AI coding agent by OpenAI — assign tasks and Codex writes, tests, and ships code in a sandboxed environment.
Codex is OpenAI's cloud-based AI coding agent, available inside ChatGPT. Assign tasks in plain English — fix a bug, add a feature, refactor a module — and Codex reads your codebase, writes the code, runs tests, and submits a pull request. Each task runs in its own sandboxed cloud environment with your full repository loaded. Run multiple tasks in parallel and review the results when ready. Built on the codex-1 model, optimized for software engineering with strong instruction following and iterative test-fix loops.
Tags: AI, Coding, Developer Tools, OpenAI
Try CodexCodex is available to ChatGPT Pro, Team, and Enterprise users. It's included in those plans at no extra cost.
ChatGPT helps you write code in chat. Codex is an autonomous agent that operates on your actual codebase — reading files, writing code, running tests, and creating pull requests.
Codex works with any programming language in your repository — it reads and writes code based on context, not a fixed language list.