Installation & Setup

This chapter will guide you through the installation and initial configuration process for Claude Code.

Installing Claude Code

Prerequisites

• Node.js >= 18.x
• Valid Anthropic API key

Installation Steps

1. Get Claude Code

   Visit the Claude Code website to get the latest version.

2. Set up API Key

   export ANTHROPIC_API_KEY=your_api_key_here

3. Verify Installation

   claude --version

Initial Configuration

Create CLAUDE.md File

Create a CLAUDE.md file in your project root:

# CLAUDE.md

This is my project configuration file that Claude will automatically read.

## Common Commands
- npm run build: Build the project
- npm run test: Run tests
- npm run lint: Code linting

## Project Standards
- Use TypeScript
- Follow ESLint rules
- Prefer functional components

Configure Tool Permissions

On first run, Claude Code will request tool permissions. Recommended:

1. Always allow:

   • Read - File reading
   • Write - File writing
   • Bash(git *) - Git commands

2. Use with caution:

   • Bash(rm *) - Delete commands
   • Bash(sudo *) - Admin privileges

Environment Variables

Add to your .bashrc or .zshrc:

# Claude Code Configuration
export CLAUDE_CONFIG_PATH="$HOME/.claude"
export CLAUDE_DEFAULT_MODEL="claude-3-sonnet"

Verify Configuration

Run this command to verify your setup:

claude -p "Read the README.md file in current directory and summarize it"

If everything is working correctly, Claude Code will read and summarize your README file.

Common Issues

Q: API key not recognized

A: Ensure environment variables are set correctly, restart terminal and try again.

Q: Permission denied

A: Check file permissions, ensure Claude Code can access the target directory.

Q: Cannot connect to service

A: Check network connection and API service status.

Next: Basic Usage - Learn basic Claude Code operations.