Claude Code Configuration Guide

Learn how to configure Claude Code for optimal performance in your development workflow. This guide covers global settings, project-specific configuration, and integration options.

🔧 Configuration Overview

Claude Code uses a hierarchical configuration system:

1. Global Configuration - User-wide settings
2. Project Configuration - Project-specific overrides
3. Session Configuration - Runtime flags and options

📁 Configuration Files

Global Configuration

Located in your home directory:

• ~/.claude/config.json - Main configuration file

  {
    "defaultModel": "opus-4",
    "theme": "dark",
    "editor": "vscode",
    "autoSave": true,
    "contextWindow": 200000
  }

• ~/.claude/CLAUDE.md - Personal preferences and instructions

  # Personal Claude Code Instructions
   
  - Always use TypeScript over JavaScript
  - Prefer functional programming patterns
  - Include comprehensive error handling
  - Write detailed commit messages

Project Configuration

Located in your project root:

• ./CLAUDE.md - Project-specific instructions

  # Project Instructions for Claude Code
   
  - Follow the project's ESLint configuration
  - Use the existing design system components
  - All new features require unit tests
  - Database migrations must be reversible

• ./.claudeignore - Files and directories to exclude

  # Dependencies
  node_modules/
  vendor/
  
  # Build outputs
  dist/
  build/
  *.min.js
  
  # Sensitive files
  .env
  .env.local
  *.key
  *.pem
  
  # Large files
  *.log
  *.sql
  *.zip
  

• ./claude.config.js - Advanced programmatic configuration

  module.exports = {
    // Model preferences
    models: {
      default: 'opus-4',
      fallback: 'sonnet-3.5'
    },
    
    // Context management
    context: {
      maxFiles: 100,
      maxFileSize: '1MB',
      includePatterns: ['src/**/*', 'tests/**/*'],
      excludePatterns: ['**/*.test.js']
    },
    
    // Custom hooks
    hooks: {
      beforeEdit: './scripts/format.js',
      afterEdit: './scripts/lint.js',
      onCommit: './scripts/test.js'
    },
    
    // Tool integrations
    tools: {
      mcp: {
        servers: ['github', 'jira', 'slack']
      }
    }
  };

🎛️ Configuration Options

Core Settings

Setting	Description	Default
defaultModel	AI model to use	opus-4
contextWindow	Maximum context size	200000
autoSave	Auto-save edited files	true
theme	UI theme	system
editor	Preferred editor	auto-detect

Advanced Settings

Setting	Description	Default
parallelEdits	Allow concurrent file edits	false
syntaxValidation	Validate syntax before save	true
testGeneration	Auto-generate tests	prompt
commitStyle	Git commit format	conventional
codeStyle	Formatting preferences	project

Security Settings

Setting	Description	Default
allowShellCommands	Execute shell commands	true
sandboxMode	Restrict file system access	false
auditLog	Log all actions	false
encryption	Encrypt sensitive data	true

🔌 Environment Variables

Essential environment variables:

# API Configuration
export ANTHROPIC_API_KEY=your-api-key-here
 
# Optional Settings
export CLAUDE_HOME=$HOME/.claude
export CLAUDE_EDITOR=vscode
export CLAUDE_MODEL=opus-4
export CLAUDE_LOG_LEVEL=info

🎨 Customization Examples

For Web Development

// claude.config.js
module.exports = {
  context: {
    includePatterns: ['src/**/*', 'public/**/*', 'package.json'],
    excludePatterns: ['node_modules', 'dist', '**/*.min.js']
  },
  tools: {
    linters: ['eslint', 'prettier'],
    bundler: 'webpack',
    framework: 'react'
  }
};

For Python Projects

// claude.config.js
module.exports = {
  context: {
    includePatterns: ['**/*.py', 'requirements.txt', 'setup.py'],
    excludePatterns: ['__pycache__', '*.pyc', 'venv/']
  },
  tools: {
    linters: ['pylint', 'black'],
    testRunner: 'pytest',
    packageManager: 'pip'
  }
};

For Monorepos

// claude.config.js
module.exports = {
  context: {
    workspaces: ['packages/*', 'apps/*'],
    sharedConfig: '.eslintrc.js',
    rootFiles: ['package.json', 'lerna.json']
  },
  monorepo: {
    type: 'lerna',
    parallel: true,
    hoistDependencies: true
  }
};

🚀 Quick Configuration Tips

1. Start Simple: Begin with basic CLAUDE.md instructions
2. Evolve Gradually: Add configuration as needed
3. Document Changes: Keep configuration well-commented
4. Version Control: Track configuration files in git
5. Team Alignment: Share configuration with your team

🔗 Related Documentation

• Quickstart Guide - Get started quickly
• CLAUDE.md Reference - Detailed instruction format
• Tool Integration - Connect external tools
• Troubleshooting - Common configuration issues

🧭 Quick Navigation

← Getting Started | Documentation | Core Features | Reference