Install and Configure Codex

Codex Introduction

Codex is a local AI programming assistant provided by OpenAI that offers intelligent code completion, code explanation, and error fixing capabilities in your local environment. As a local AI coding tool within the OpenAI ecosystem, Codex supports two authentication methods: ChatGPT account and API Key.

Use Cases

• OpenAI Ecosystem Integration: If you’re already using ChatGPT or other OpenAI services, Codex integrates seamlessly
• Simple Authentication Preference: Supports direct login with ChatGPT account, no separate API Key configuration needed
• International Network Environment: Best experience in network environments with direct access to OpenAI services
• Hagicode Multi-Model Support: As one of Hagicode’s executor options, supports multi-model switching

Installation

NPM Installation

You can easily install Codex via NPM. Make sure you have Node.js installed.

npm install -g @openai/codex

After installation, verify the installation with:

codex --version

Authentication

Codex supports two authentication methods: ChatGPT account login (recommended) or API Key.

Using ChatGPT Account

This is the simplest method, requiring no separate API Key configuration.

codex login

After running this command, Codex will open a browser to guide you through the ChatGPT account login process.

Tip

Advantages of using ChatGPT account login:

• Simple configuration, no need to manage API Keys separately
• Automatically syncs your ChatGPT subscription status
• Supports using the same account across multiple devices

Using API Key

If you prefer to use API Key for authentication, follow these steps.

1. Visit OpenAI API Keys page
2. Create a new API Key
3. Set environment variable:

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

Or add the following to your Shell configuration file (like ~/.bashrc or ~/.zshrc):

echo 'export OPENAI_API_KEY="your-api-key-here"' >> ~/.bashrc
source ~/.bashrc

Tip

Advantages of using API Key:

• Precise control over API usage and costs
• Suitable for use in server or CI/CD environments
• Can share the same API Key across multiple tools

Basic Usage

First Run

After completing installation and authentication configuration, you can start using Codex:

codex

On first run, Codex will guide you through initial configuration, including:

• Selecting default model
• Configuring proxy settings (if needed)
• Setting preference options

Common Commands

Here are the common commands for Codex:

# Start Codex interactive mode
codex

# View Codex version information
codex --version

# View help information
codex --help

# Login with ChatGPT account
codex login

# Logout
codex logout

# View current configuration
codex config

# Run a one-time query
codex ask "How to implement a quicksort algorithm?"

Important Notes

Network Requirements

Codex needs to access OpenAI services, so there are certain network environment requirements:

• International Network: Use directly without additional configuration
• Domestic Network: Requires proxy configuration or network optimization services

If you’re using Codex in a domestic network environment, it’s recommended to:

1. Configure system-level proxy
2. Set HTTP/HTTPS proxy environment variables:

export HTTP_PROXY="http://proxy.example.com:8080"
export HTTPS_PROXY="http://proxy.example.com:8080"

3. Or set proxy in Codex configuration file

Pricing Plans

Codex uses OpenAI’s API services with the following billing methods:

• ChatGPT Plus Subscription: If you have a ChatGPT Plus subscription, you can use Codex without additional payment
• API Pay-as-you-go: When using API Key, billing is based on actual usage. For specific rates, please refer to the OpenAI Pricing page

Tip

It’s recommended to first experience Codex using a ChatGPT account login, then decide whether to use API Key pay-as-you-go based on your actual needs.

---

💡 Tip: For more detailed information, please visit the Codex Official Documentation.