Unleash Your Terminal: A Deep Dive into OpenAI Codex CLI

Stop wasting time on setup and start building. The OpenAI Codex CLI brings ChatGPT-level reasoning directly to your terminal, letting you manipulate files and execute code with ease. Ready to revolutionize your development workflow?

Why You Need Codex CLI in Your Life

• Zero Setup: Skip the configuration headaches and jump straight into coding. All you need is your OpenAI API key.
• Full Auto-Approval (Safely!): Code execution happens inside sandboxed and network-disabled environments for maximum security.
• Multimodal Input: Implement features using screenshots and diagrams (✨!).
• Open Source: Contribute to the future of AI-powered development.

Setting Up Codex CLI in Minutes

1. Install Globally:

   npm install -g @openai/codex
   

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2. Set Your OpenAI API Key:

   export OPENAI_API_KEY="your-api-key-here"
   

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   Make this permanent by adding it to your shell's configuration file (e.g., ~/.zshrc). Or, you can simply place your API key into a .env file at the root of your project.
3. Run Interactively:

   codex " explain this codebase to me "
   

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4. Run with a Prompt (and Full Auto Mode):

   codex --approval-mode full-auto " create the fanciest todo-list app "
   

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Codex will scaffold files, run them in a sandbox, install dependencies, and show you the result. Approve the changes, and they'll be committed.

Harnessing the Power of Codex: Real-World Examples

• Codebase Explanation: Quickly understand complex code structures with simple prompts.
• Automated To-Do App Generation: Build functional applications from scratch with minimal effort.
• Changelog Updates: Simplify your release process by automatically generating changelogs.

Security First: Understanding Permissions and Sandboxing

Codex CLI balances power with safety. Choose your desired level of automation using the --approval-mode flag.

• Full Auto: Commands run network-disabled and sandboxed to your working directory.
• macOS users (12+): Benefit from Apple Seatbelt sandboxing, creating a read-only jail with limited writable roots.
• Linux users: Docker sandboxing is recommended for deterministic and reproducible runs. Configure using the run_in_container.sh script.

Taming Codex: Configuration & Custom Instructions

Personalize Codex to fit your coding style with custom configurations.

• ~/.codex/config.yaml: Set default models, auto-approval error modes, and enable notifications.
• ~/.codex/instructions.md: Define your coding preferences (e.g., "Always respond with emojis").

Fine-Tuning Codex CLI with Project Docs

Codex intelligently merges Markdown instructions from various locations:

• ~/.codex/instructions.md: Global, personal guidance.
• codex.md (repo root): Shared project notes.
• codex.md (cwd): Sub-package specifics.

Disable project docs with --no-project-doc or CODEX_DISABLE_PROJECT_DOC=1.

Seamless CI/CD Integration

Integrate Codex CLI into your CI/CD pipelines for automated tasks.

- name: Update changelog via Codex
  run: |
    npm install -g @openai/codex
    export OPENAI_API_KEY="${{ secrets.OPENAI_KEY}}"
    codex -a auto-edit --quiet "update CHANGELOG for next release"

Set CODEX_QUIET_MODE=1 to suppress interactive UI elements in CI environments.

Contribute and Shape the Future

Want to help build the ultimate coding companion? Contribute to the open-source project!

1. Create a topic branch from main.
2. Focus your changes.
3. Use npm run test:watch for rapid feedback.
4. Adhere to linting and type-checking standards.

This is your chance to contribute to a coding agent that's reshaping development workflows!

Contribute and Help Fund the Future of Codex CLI

We encourage open source projects that use Codex CLI by offering them a $1 million initiative. Grants are awarded in $25,000 API credit increments.

Steer Clear of Zero Data Retention (ZDR) Limitations

Currently, Codex CLI is incompatible with OpenAI organizations that have enabled the Zero Data Retention policy. Support will be added in the future.