OpenAI Codex

Codex is OpenAI's autonomous coding agent: it reads, writes, and runs code in your repository, and is available as a terminal CLI, a desktop app, an IDE extension, or built directly into ChatGPT.

Delegate complete development tasks (writing features, fixing bugs, refactoring, writing tests) to an agent that runs commands and verifies its own changes inside a controlled sandbox environment.

When you already use ChatGPT Plus/Pro and want a coding agent built into the same ecosystem, with the flexibility to also work from the CLI or an IDE.

1. Enable Codex from your ChatGPT account (Plus, Pro, or Business) or install the CLI from developers.openai.com/codex
2. Connect the repository you want to work on
3. Describe the task in natural language (e.g. 'fix this bug' or 'add this feature')
4. Review the plan of changes it proposes before approving it
5. Let it run commands and tests inside the sandbox and review the final result

Included with limited usage in ChatGPT Free; more capacity in Plus ($20/month) and Pro ($100-$200/month); also available through the API with pay-as-you-go pricing.