npm i -g @openai/codex
or brew install --cask codex

Codex CLI is a coding agent from OpenAI that runs locally on your computer.

If you want Codex in your code editor (VS Code, Cursor, Windsurf), install in your IDE.
If you want the desktop app experience, run codex app or visit the Codex App page.
If you are looking for the cloud-based agent from OpenAI, Codex Web, go to chatgpt.com/codex.

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Quickstart

Installing Codex with Speckit Support (Required)

To use the Specify/Speckit commands, you must build Codex from this repository:

1. Install Rust: If you haven't already, install Rust via rustup.rs.

2. Clone the repository:

   git clone https://github.com/0xhalil/codex.git
   cd codex

3. Build and Install:

   cargo install --path codex-cli

   This will compile Codex and install the codex binary to your ~/.cargo/bin directory.

4. Run: Run the binary directly to ensure you are using the version with Speckit support:

   ~/.cargo/bin/codex

   (Or simply codex if ~/.cargo/bin is in your PATH.)

Official Release (Legacy/Public)

Install globally with your preferred package manager:

# Install using npm
npm install -g @openai/codex

# Install using Homebrew
brew install --cask codex

Then simply run codex to get started.

You can also go to the latest GitHub Release and download the appropriate binary for your platform.

Each GitHub Release contains many executables, but in practice, you likely want one of these:

• macOS
  • Apple Silicon/arm64: codex-aarch64-apple-darwin.tar.gz
  • x86_64 (older Mac hardware): codex-x86_64-apple-darwin.tar.gz
• Linux
  • x86_64: codex-x86_64-unknown-linux-musl.tar.gz
  • arm64: codex-aarch64-unknown-linux-musl.tar.gz

Each archive contains a single entry with the platform baked into the name (e.g., codex-x86_64-unknown-linux-musl), so you likely want to rename it to codex after extracting it.

Using Codex with your ChatGPT plan

Run codex and select Sign in with ChatGPT. We recommend signing into your ChatGPT account to use Codex as part of your Plus, Pro, Team, Edu, or Enterprise plan. Learn more about what's included in your ChatGPT plan.

You can also use Codex with an API key, but this requires additional setup.

Specify (Speckit) Integration

Codex now supports Speckit commands natively within the TUI. This allows you to load project-specific context and prompts directly from your project's configuration.

How to use

1. Initialize Project: To enable Specify commands, initialize Specify in your project directory targeting the Codex agent structure:

   specify init --agent codex

   This creates the necessary .codex/prompts/ directory with standard templates.

2. Run Codex: Run the binary directly to ensure you are using the version with Speckit support:

   ~/.cargo/bin/codex

   (Or simply codex if ~/.cargo/bin is in your PATH.)

3. Use Commands:

   • Type /specify. in the input box to see a list of available Specify commands.
   • You can also type the command name directly (e.g., /plan, /constitution) to find and execute them.

Note: Codex prioritizes configuration in .codex/prompts/ over legacy .gemini/commands/ directories.

Docs

• Codex Documentation
• Contributing
• Installing & building
• Open source fund

This repository is licensed under the Apache-2.0 License.