Claude Code is Anthropic’s AI-powered coding assistant that lives in your terminal. Unlike chat-based coding helpers, it can actually read your files, run commands, and make changes.

This guide covers everything you need to get productive fast.

What is Claude Code?

Claude Code is a CLI tool that:

  • Reads and understands your entire codebase
  • Makes edits across multiple files
  • Runs tests and commands
  • Explains code and suggests improvements

Think of it as a senior developer who never gets tired and has read every Stack Overflow answer.

Getting Started

Install via npm:

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

Then start a session:

claude

That’s it. Claude will automatically detect your project structure.

Essential Commands

Reading Files

> Read the authentication middleware and explain how it works

Claude reads the file, understands the code, and explains it in plain English.

Making Changes

> Add rate limiting to the /api/users endpoint

Claude will:

  1. Find the relevant file
  2. Show you the proposed changes
  3. Apply them after confirmation

Running Commands

> Run the tests and fix any failures

Claude executes npm test, reads the output, and proposes fixes.

Real-World Workflows

Bug Fixing

> There's a bug where users can't log in after password reset.
> Find and fix it.

Claude will:

  1. Search for password reset related code
  2. Trace the authentication flow
  3. Identify the bug
  4. Propose and apply a fix

Feature Development

> Add a "forgot password" feature with email verification

Claude creates:

  • New API endpoints
  • Email templates
  • Database migrations
  • Frontend components
  • Tests

Code Review

> Review the changes in the last commit for security issues

Claude reads the diff and provides feedback like a senior engineer.

Advanced Patterns

Multi-File Refactoring

> Refactor the user service to use the repository pattern

Claude understands architectural patterns and applies them consistently across your codebase.

Test-Driven Development

> Write tests for the payment service, then implement it

Claude writes comprehensive tests first, then implements code that passes them.

Documentation

> Generate API documentation for all endpoints in /routes

Claude reads your code and generates accurate, up-to-date docs.

Tips for Better Results

Be Specific

❌ “Fix the bug” ✅ “Fix the bug where the cart total doesn’t update when removing items”

Provide Context

❌ “Add authentication” ✅ “Add JWT authentication using our existing User model and bcrypt for passwords”

Iterate

Don’t expect perfection on the first try. Review, give feedback, and refine.

When to Use Claude Code vs. Other Tools

TaskBest Tool
Quick questionsChatGPT/Claude.ai
Code completionCopilot
Multi-file changesClaude Code
Debugging complex issuesClaude Code
Architecture decisionsClaude Code

Limitations

Be aware that Claude Code:

  • Can make mistakes (always review changes)
  • May not know about very recent libraries
  • Works best with common languages/frameworks
  • Requires your judgment for business logic

Security Considerations

Claude Code runs in your terminal and can execute commands. Best practices:

  1. Review all proposed changes before accepting
  2. Don’t use on production systems
  3. Be careful with sensitive data in prompts
  4. Use in version-controlled directories

Conclusion

Claude Code is a force multiplier for developers. It won’t replace your skills, but it will amplify them.

Start with small tasks, build trust, and gradually give it more complex work. You’ll be amazed at what you can accomplish.

Want to level up your development workflow? Let’s chat about AI-assisted development.