Codex
OpenAI's AI coding agent for the terminal. Understands your repo, writes and runs code autonomously.
In plain English
Like Claude Code but from OpenAI. Another senior developer in your terminal. Different personality, same idea: describe what you want, it builds it.
Real-world example
You tell Codex 'write tests for all the API endpoints in this project.' It reads your routes, generates test files, and runs them to make sure they pass.
Where this fits in your project
OpenAI's terminal-based AI coding agent. Same category as Claude Code and Gemini CLI.
When to use this
When you want a terminal AI agent and prefer OpenAI's models.
The situation
You want a terminal AI agent and want to compare options or prefer GPT models.
Good for
- + Multi-file changes
- + Code generation
- + Testing
- + Working with GPT models
Not ideal for
- - People uncomfortable with terminals
- - When you need a visual editor
Getting started
Install with npm: `npm install -g @openai/codex`, then run `codex` in your project directory.