Codex

Codex is OpenAI’s AI coding agent that can answer questions about a codebase, run commands and tests in an isolated sandbox, and propose changes as draft pull requests. It runs both in the cloud and locally on your own machine. It aims to speed up code generation, refactoring, and debugging by working with real repositories and surfacing verifiable artifacts like logs and test results.

Codex is available in ChatGPT on the web, in IDE extensions for editors like VS Code, JetBrains, and Xcode, in a desktop app, and as an open-source terminal app called Codex CLI for local workflows.

It allows you to provide an AGENTS.md file to guide behavior and environment setup. It uses engineering-tuned models and agent scaffolding.

Official website: openai.com/codex