Installing Claude Code on Any Platform

Prerequisites

Before installing Claude Code, ensure your system meets these minimum requirements:

• Operating System: macOS 10.15+, Ubuntu 20.04+ / Debian 10+, or Windows with WSL2
• Node.js: Version 18 or later (Claude Code is distributed as an npm package)
• RAM: 4 GB minimum (8 GB recommended for large projects)
• Terminal: Any modern terminal emulator (iTerm2, Alacritty, Windows Terminal, Kitty)

You can verify your Node.js version with:

node --version
# Should output v18.x.x or later

If you need to install or update Node.js, use a version manager like nvm for the smoothest experience:

# Install nvm (Node Version Manager)
curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.0/install.sh | bash

# Install the latest LTS version of Node.js
nvm install --lts
nvm use --lts

Installing on macOS

On macOS, you have two installation methods. The recommended approach uses npm directly:

# Method 1: Install globally via npm (recommended)
npm install -g @anthropic-ai/claude-code

# Method 2: Install via Homebrew
brew install claude-code

After installation, verify it works:

claude --version
# Expected output: claude-code v1.x.x

If you are using macOS and encounter permission errors with global npm installs, fix your npm prefix:

# Fix npm global permissions (one-time setup)
mkdir -p ~/.npm-global
npm config set prefix '~/.npm-global'
echo 'export PATH=~/.npm-global/bin:$PATH' >> ~/.zshrc
source ~/.zshrc

# Now install Claude Code
npm install -g @anthropic-ai/claude-code

Installing on Linux (Ubuntu/Debian)

The installation process on Linux is nearly identical:

# Ensure Node.js 18+ is installed
node --version

# Install Claude Code globally
npm install -g @anthropic-ai/claude-code

# Verify the installation
claude --version

For Linux distributions that use older Node.js packages in their default repositories, always use nvm or the NodeSource repository to get a current version:

# NodeSource method for Ubuntu/Debian
curl -fsSL https://deb.nodesource.com/setup_20.x | sudo -E bash -
sudo apt-get install -y nodejs

# Then install Claude Code
npm install -g @anthropic-ai/claude-code

Installing on Windows (WSL2)

Claude Code does not run natively on Windows. You must use Windows Subsystem for Linux 2 (WSL2), which provides a full Linux environment:

# Step 1: Install WSL2 from PowerShell (as Administrator)
wsl --install

# Step 2: Restart your computer, then open Ubuntu from Start menu

# Step 3: Inside WSL2, install Node.js
curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.0/install.sh | bash
source ~/.bashrc
nvm install --lts

# Step 4: Install Claude Code
npm install -g @anthropic-ai/claude-code

# Step 5: Verify
claude --version

Important: Always run Claude Code from within your WSL2 terminal, not from PowerShell or Command Prompt. Your project files should ideally live within the WSL2 filesystem (e.g., ~/projects/) for best performance.

Authentication Setup

After installation, you need to authenticate Claude Code with an API provider. Claude Code supports three authentication methods:

Method 1: Anthropic API Key (Direct)

This is the simplest method for individual developers:

# Start Claude Code — it will prompt for authentication on first run
claude

# Or set the API key as an environment variable
export ANTHROPIC_API_KEY="sk-ant-api03-your-key-here"

# Add to your shell profile for persistence
echo 'export ANTHROPIC_API_KEY="sk-ant-api03-your-key-here"' >> ~/.zshrc

Method 2: Claude Teams / Enterprise (OAuth)

If your organization uses Claude Teams or Claude Enterprise:

# Launch Claude Code and select "Claude Teams" at the auth prompt
claude

# Follow the browser-based OAuth flow
# Your credentials are cached securely after first login

Method 3: AWS Bedrock

For organizations routing through AWS Bedrock:

# Set the required environment variables
export CLAUDE_CODE_USE_BEDROCK=1
export AWS_REGION=us-east-1
export AWS_ACCESS_KEY_ID="your-access-key"
export AWS_SECRET_ACCESS_KEY="your-secret-key"

# Start Claude Code
claude

Method 4: Google Vertex AI

For teams using Google Cloud's Vertex AI:

# Set the required environment variables
export CLAUDE_CODE_USE_VERTEX=1
export CLOUD_ML_REGION=us-east5
export ANTHROPIC_VERTEX_PROJECT_ID=your-gcp-project-id

# Authenticate with Google Cloud
gcloud auth application-default login

# Start Claude Code
claude

Troubleshooting Common Issues

# Diagnostic commands for troubleshooting
which claude              # Check if claude is in PATH
npm list -g --depth=0     # Verify global installation
echo $ANTHROPIC_API_KEY   # Check if API key is set (careful with logging)
claude --version          # Confirm installed version

Updating Claude Code

Claude Code receives frequent updates with new features and model improvements. Keep it current:

# Update to the latest version
npm update -g @anthropic-ai/claude-code

# Or with Homebrew on macOS
brew upgrade claude-code

Key Takeaways

• Claude Code installs via npm (npm install -g @anthropic-ai/claude-code) and requires Node.js 18 or later
• On Windows, you must use WSL2 — there is no native Windows support
• Authentication supports four methods: direct API key, Claude Teams OAuth, AWS Bedrock, and Google Vertex AI
• Always verify your installation with claude --version before starting your first session
• Use nvm to manage Node.js versions and avoid permission issues with global npm packages