Installation & Configuration

This guide helps you install and configure Claude Code on different platforms.

System Requirements

• Operating System: macOS, Linux, or Windows
• Node.js: v18 or higher
• Network: Access to Anthropic API required

Installation

macOS / Linux

# Install using npm
npm install -g @anthropic-ai/claude-code

# Or use Homebrew
brew install anthropics/claude/claude

# Verify installation
claude --version

Windows

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

Configure API Key

Method 1: Environment Variable (Recommended)

# macOS/Linux - Add to ~/.zshrc
export ANTHROPIC_API_KEY='sk-ant-...'

# Windows PowerShell
$env:ANTHROPIC_API_KEY = "sk-ant-..."

Method 2: Configuration File

claude config set apiKey sk-ant-...

Verify Configuration

claude --version
claude config list

First Launch

cd your-project
claude

Claude Code v2.1.0
Working directory: /Users/you/project

You: Help me analyze the project structure

After launching, press Shift+Tab to cycle through permission modes:

Normal Mode → Auto-Accept Mode → Plan Mode → Normal Mode

- Normal Mode: Default, each operation requires confirmation
- Auto-Accept Mode: Auto-execute (bottom shows ⏵⏵ accept edits on)
- Plan Mode: Read-only (bottom shows ⏸ plan mode on)

Project Configuration

Create a CLAUDE.md file in your project root, and Claude will load it automatically:

# Project Description

## Tech Stack
- React 18
- TypeScript 5
- Vite

## Common Commands
- Development: `npm run dev`
- Testing: `npm test`
- Build: `npm run build`

You can also configure permissions in .claude/settings.json:

{
  "permissionMode": "custom",
  "allowedPaths": ["src/**", "tests/**"],
  "blockedPaths": [".env", "secrets/**"],
  "allowedCommands": ["npm test", "npm run build"]
}

Amazon Bedrock Configuration

If using AWS Bedrock instead of the direct Anthropic API:

export AWS_ACCESS_KEY_ID='your-access-key'
export AWS_SECRET_ACCESS_KEY='your-secret-key'
export AWS_REGION='us-east-1'

claude config set provider bedrock

FAQ

Invalid API Key:

echo $ANTHROPIC_API_KEY    # Check if set
claude config set apiKey sk-ant-...  # Re-set

Command not found:

which claude              # Check installation path
npm install -g @anthropic-ai/claude-code  # Re-install

Network connection issues:

export HTTPS_PROXY=http://proxy:8080  # Use proxy

Next Steps

• First Conversation
• Getting Started
• CLI Reference