Claude Code Installation and Usage Guide: AI Programming Assistant Setup

Claude Code is a powerful AI programming assistant that allows you to collaborate with AI directly in your terminal. This guide will walk you through the installation and configuration process.

📋 System Requirements#

• Node.js version ≥ 18.0
• Supported operating systems: macOS, Linux, Windows (WSL)

🚀 Quick Start#

1. Install Node.js#

💡 Tip: If you already have Node.js 18.0 or higher installed, you can skip this step.

Ubuntu / Debian Users#

# Install Node.js LTS version
curl -fsSL https://deb.nodesource.com/setup_lts.x | sudo bash -
sudo apt-get install -y nodejs

# Verify installation
node --version

macOS Users#

# Install Xcode command line tools
sudo xcode-select --install

# Install Homebrew (if not already installed)
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

# Install Node.js via Homebrew
brew install node

# Verify installation
node --version

2. Install Claude Code#

Install Claude Code globally using npm:

npm install -g @anthropic-ai/claude-code

# Verify installation
claude --version

3. Configure and Start Using#

Obtain Required Configuration Information#

You need to prepare two important configuration items:

📝 Recommended settings when creating a token:

• Name: Any name you prefer
• Quota: Set to unlimited
• Group: Select Claude Code dedicated or Official Claude 3 and above
• Other options: Keep default settings

Launch Claude Code#

Run in your project directory:

Linux / macOS:

# Navigate to project directory
cd your-project-folder

# Set environment variables
export ANTHROPIC_AUTH_TOKEN=sk-...  # Replace with your actual token
export ANTHROPIC_BASE_URL=https://ai.crazyrouter.us/
export API_TIMEOUT_MS=300000  # Set to 300 seconds timeout

# Launch Claude Code
claude

Windows PowerShell:

# Navigate to project directory
cd your-project-folder

# Set environment variables
$env:ANTHROPIC_BASE_URL = "https://ai.crazyrouter.us/"
$env:ANTHROPIC_AUTH_TOKEN = "sk-..."
$env:API_TIMEOUT_MS = "300000"

# Launch Claude Code
claude

Windows CMD:

# Navigate to project directory
cd your-project-folder

# Set environment variables
set ANTHROPIC_BASE_URL=https://ai.crazyrouter.us/
set ANTHROPIC_AUTH_TOKEN=sk-...
set API_TIMEOUT_MS=300000

# Launch Claude Code
claude

First Run Configuration#

After launching, you will see the following configuration steps:

1. Select Theme → Choose your preferred theme + Press Enter
2. Safety Notice → Confirm safety notice + Press Enter
3. Terminal Configuration → Use default configuration + Press Enter
4. Working Directory Trust → Trust current directory + Press Enter

✨ Congratulations! Now you can start coding with your AI programming partner!

❓ FAQ#

Q: Getting "Invalid API Key · Please run /login" error?#

A: This indicates Claude Code didn't detect the environment variables. Please check:

• Whether ANTHROPIC_AUTH_TOKEN and ANTHROPIC_BASE_URL are set correctly
• Whether environment variable values are correct (token starts with sk-)
• If using permanent configuration, whether you restarted the terminal

Q: Why does it show "offline" status?#

A: Claude Code checks network status by connecting to Google. Showing "offline" doesn't affect normal usage; it just indicates inability to connect to Google.

Q: Why does web page Fetch fail?#

A: Claude Code needs to call Claude service for security checks before accessing web pages. You need to:

• Maintain a stable international internet connection
• Use a global proxy if necessary

Q: Requests always show "fetch failed"?#

A: This may be caused by network environment issues. Solution:

1. Try using a proxy tool
2. Check your network connection

Q: How to handle API errors?#

A: This may be caused by unstable forwarding proxy. Recommendations:

• Exit Claude Code (Ctrl+C)
• Re-run the claude command
• If the problem persists, try again later

Q: Web login error?#

A: Try clearing the site's cookies, then log in again.

📌 Notes#

• This site directly connects to the official Claude Code forwarding service
• Only supports Claude Code API traffic, not other API calls
• Please keep your API token secure and avoid leakage

🔗 Related Links#

• Claude Code Official Documentation
• Node.js Official Website
• Crazyrouter — Access Claude Code at lower cost

💡 Tip: If you encounter other issues, please check the official documentation or contact technical support.