Codex CLI

Relevant Links

• Announcement Blog
• GitHub Repo

An agentic CLI provided by OpenAI. They have an open source GitHub repo. Zero setup - bring your OpenAI API key and it just works!

Providers you can use:

• openai (default)
• openrouter
• azure
• gemini
• ollama
• mistral
• deepseek
• xai
• groq
• arceeai
• any other provider that is compatible with the OpenAI API

---

Installation

Upgrade Codex

You can upgrade Codex with your preferred package manager:

Upgrade with npm

npm install -g @openai/codex@latest

Upgrade with Homebrew

brew upgrade codex

Commands

---

Configuration

CLI Config Documentation

---

Additional Tips and Tricks

Why does o3 or o4-mini not work for me?

It’s possible that your API account needs to be verified in order to start streaming responses and seeing chain of thought summaries from the API. If you’re still running into issues, please let us know!

Which models are supported?

Any model available with Responses API. The default is o4-mini, but pass --model gpt-4.1 or set model: gpt-4.1 in your config file to override.

Memory & Project Docs

You can give Codex extra instructions and guidance using AGENTS.md files. Codex looks for AGENTS.md files in the following places, and merges them top-down:

1. ~/.codex/AGENTS.md - personal global guidance
2. AGENTS.md at repo root - shared project notes
3. AGENTS.md in the current working directory - sub-folder/feature specifics

Disable loading of these files with --no-project-doc or the environment variable CODEX_DISABLE_PROJECT_DOC=1.

Tracing / verbose logging

Setting the environment variable DEBUG=true prints full API request and response details:

DEBUG=true codex

---

Use Cases

Below are a few bite-size examples you can copy-paste. Replace the text in quotes with your own task. See the prompting guide for more tips and usage patterns.

✨	What you type	What happens
1	codex "Refactor the Dashboard component to React Hooks"	Codex rewrites the class component, runs npm test, and shows the diff.
2	codex "Generate SQL migrations for adding a users table"	Infers your ORM, creates migration files, and runs them in a sandboxed DB.
3	codex "Write unit tests for utils/date.ts"	Generates tests, executes them, and iterates until they pass.
4	codex "Bulk-rename *.jpeg -> *.jpg with git mv"	Safely renames files and updates imports/usages.
5	codex "Explain what this regex does: ^(?=.*[A-Z]).{8,}$"	Outputs a step-by-step human explanation.
6	codex "Carefully review this repo, and propose 3 high impact well-scoped PRs"	Suggests impactful PRs in the current codebase.
7	codex "Look for vulnerabilities and create a security review report"	Finds and explains security bugs.