How to Install Claude Code CLI on Windows, macOS, and Linux

Claude Code is Anthropic’s official AI coding assistant that runs directly in your terminal. It reads your files, writes and edits code, runs commands, and works across your entire project without leaving the command line. This guide walks you through the full installation process on every major platform, covers all three authentication methods, and fixes the most common errors you will run into.

System Requirements for Claude Code CLI

Before you install Claude Code, confirm your machine meets these minimum specs:

Check your current Node.js version before proceeding:

node --version

If the output shows a version below 18, update Node.js first. You can download the latest LTS from nodejs.org or use nvm to manage versions.

Install Claude Code Using the Native Installer (Fastest Method)

Anthropic now ships native installers as the recommended path. These require no Node.js setup and complete in under 60 seconds.

Windows (PowerShell, run as Administrator):

irm https://claude.ai/install.ps1 | iex

macOS and Linux:

curl -fsSL https://claude.ai/install.sh | bash

macOS via Homebrew:

brew install --cask claude-code

After the installer finishes, run this to confirm success:

claude --version

A version number in the output means the installation worked. If the command returns an error, follow the platform-specific steps below.

How to Install Claude Code on macOS

Step 1: Install Node.js (if not already installed)

Use Homebrew to install Node.js:

brew install node

If you do not have Homebrew, download Node.js directly from nodejs.org.

Step 2: Install Claude Code via npm

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

Step 3: Verify the Installation

claude --version

The terminal prints a version number like 1.x.x if installation succeeded.

Step 4: Authenticate

claude auth login

This command opens a browser window where you log in with your Anthropic account.

Fix for PATH errors (zsh users):

If macOS reports command not found: claude after installation, add npm’s bin directory to your PATH:

echo 'export PATH="$(npm config get prefix)/bin:$PATH"' >> ~/.zshrc
source ~/.zshrc

How to Install Claude Code on Linux

Step 1: Install Node.js

Ubuntu and Debian:

curl -fsSL https://deb.nodesource.com/setup_20.x | sudo -E bash -
sudo apt-get install -y nodejs

For Fedora, Arch, or other distributions, use your package manager or install via nvm.

Step 2: Configure npm to Avoid Permission Errors

Never run sudo npm install -g. Set a user-level npm directory instead:

mkdir ~/.npm-global
npm config set prefix '~/.npm-global'
echo 'export PATH=~/.npm-global/bin:$PATH' >> ~/.bashrc
source ~/.bashrc

Step 3: Install Claude Code

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

Step 4: Verify and Authenticate

claude --version
claude auth login

How to Install Claude Code on Windows

Option 1: Native Installer (Recommended)

Open PowerShell as Administrator and run:

irm https://claude.ai/install.ps1 | iex
claude --version

This method requires no Node.js.

Option 2: Git Bash

Install Git for Windows, then open Git Bash and run:

curl -fsSL https://claude.ai/install.sh | bash
claude --version

Option 3: WSL (Ubuntu)

# Run in PowerShell as Administrator
wsl --install -d Ubuntu

Then open the Ubuntu terminal and run:

curl -fsSL https://claude.ai/install.sh | bash
claude --version

Option 4: npm on Windows

Download the Node.js Windows installer from nodejs.org. During installation, check the “Add to PATH” option. Then open PowerShell or Windows Terminal and run:

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

If Windows does not recognize the claude command after installation, run this to find the npm global bin path:

npm config get prefix

Add that path to your system PATH environment variable, then restart your terminal.

Authenticate after installation:

claude auth login

Authentication Methods

Claude Code supports three ways to authenticate.

Method 1: OAuth Login (Easiest)

claude auth login

This opens a browser window and logs you in via your Anthropic account. Use this method if you have a Pro or Max subscription.

Method 2: API Key (Best for API Credits)

Set your API key as an environment variable.

macOS and Linux:

export ANTHROPIC_API_KEY="sk-ant-..."
echo 'export ANTHROPIC_API_KEY="sk-ant-..."' >> ~/.zshrc  # or ~/.bashrc

Windows (PowerShell):

[System.Environment]::SetEnvironmentVariable('ANTHROPIC_API_KEY', 'sk-ant-...', 'User')

Generate your API key at console.anthropic.com under Settings > API Keys.

Method 3: Config File

Edit or create ~/.claude/auth/credentials.json:

{
  "api_key": "sk-ant-...",
  "auth_type": "api_key"
}

Verify Your Installation Works

After authentication, run a quick functionality test.

Open the Claude Code REPL:

claude

Type a prompt at the cursor:

Hello! What model are you running?

Claude responds with a greeting and the active model name. That confirms the setup works end to end.

Test file reading:

cd ~/projects/my-app
claude

Then enter:

Can you read the README.md and summarize this project?

If Claude reads and summarizes the file, your installation is fully working.

Run diagnostics anytime:

claude doctor

This command auto-detects most configuration problems and suggests fixes.

Common Claude Code Installation Errors and Fixes

Error: npm ERR! EACCES Permission Denied

This error means npm cannot write to its global folder. Fix it by switching to a user-level directory instead of using sudo:

mkdir ~/.npm-global
npm config set prefix '~/.npm-global'
export PATH=~/.npm-global/bin:$PATH

Add the export line to your ~/.zshrc or ~/.bashrc to make the change permanent.

Error: command not found: claude

The claude binary exists but your shell cannot find it. Check these causes:

1. Terminal not restarted — Close and reopen your terminal.
2. PATH missing npm bin — Run echo $(npm config get prefix)/bin and add that path to PATH.
3. Wrong shell config — For zsh, edit ~/.zshrc. For bash, edit ~/.bashrc.

Error: Node.js Version Too Old

Upgrade Node.js to version 18 or later:

# macOS (Homebrew)
brew upgrade node

# Linux (nvm)
nvm install 20
nvm use 20

# Windows
# Download the latest LTS from nodejs.org

Error: Authentication Failed

Work through these checks in order:

• Confirm your API key starts with sk-ant-
• Check that the key has not been revoked at console.anthropic.com
• Remove any extra spaces in your ANTHROPIC_API_KEY environment variable
• Regenerate the key if nothing else resolves it

On remote servers or WSL where the browser does not open, skip OAuth and use the API key method instead:

export ANTHROPIC_API_KEY=sk-ant-your-key-here
claude

Error: Cannot find module ‘@anthropic-ai/claude-code’

The install did not complete. Force a clean reinstall:

npm cache clean --force
npm install -g @anthropic-ai/claude-code@latest --force

Error: EBADPLATFORM

This error appears when npm installation fails due to an unsupported platform configuration. Switch to the native installer instead:

# macOS and Linux
curl -fsSL https://claude.ai/install.sh | bash

# Windows PowerShell
irm https://claude.ai/install.ps1 | iex

Nuclear Reset (Fixes Most Persistent Issues)

When nothing else works, wipe everything and reinstall from scratch:

npm uninstall -g @anthropic-ai/claude-code
rm -rf ~/.claude ~/.npm/_cacache
npm cache clean --force
npm install -g @anthropic-ai/claude-code@latest
claude --version

Network Error or Timeout During Installation

If your network or a corporate firewall blocks npm, reset the registry and configure a proxy if needed:

npm config set registry https://registry.npmjs.org/

# Behind a corporate proxy:
npm config set proxy http://your-proxy:8080
npm config set https-proxy http://your-proxy:8080

VS Code and JetBrains Integration

Claude Code works inside popular IDEs as well as the terminal.

VS Code:

Install the Claude Code extension from the VS Code Marketplace. It connects to the Claude Code CLI you already installed and adds inline suggestions, diff views, and multi-file editing directly in the editor.

JetBrains (IntelliJ, PyCharm, WebStorm, etc.):

1. Open your JetBrains IDE.
2. Go to Settings, then Plugins, then Marketplace.
3. Search for “Claude Code.”
4. Click Install and restart the IDE.

The JetBrains plugin runs the CLI inside the IDE’s integrated terminal and displays proposed changes in the built-in diff viewer. It is currently in beta but works reliably for daily use.

Frequently Asked Questions

Related Guides

• How to Fix Claude AI API Error 401 Unauthorized (14 Fixes)
• How to Stop Hitting Claude Usage Limits: Tips That Actually Work
• How to Fix “Claude Temporarily Unavailable” Error
• Claude AI Not Working? Fix Every Common Chat Error (2026)
• How to Fix Claude Error Sending Message