Claude Code VS Code Tutorial

Complete Guide to Installing and Using Claude Code Extension

What is Claude Code Extension?

Claude Code is an official VS Code extension by Anthropic that brings Claude's advanced AI capabilities directly into your code editor. Unlike general-purpose AI assistants, Claude Code understands your entire codebase and can make intelligent, multi-file edits.

Key Advantage: Claude Code reads and understands your entire project structure, not just the current file. This enables powerful codebase-wide refactoring, bug fixes, and feature development.

Prerequisites

Step 1: Install the Extension

Method 1: From VS Code Marketplace (Recommended)

  1. Open VS Code
    • Launch Visual Studio Code
  2. Open Extensions View
    • Click the Extensions icon in the Activity Bar (left sidebar)
    • Or press Ctrl+Shift+X (Windows/Linux) or Cmd+Shift+X (Mac)
  3. Search for Claude Code
    • Type "Claude Code" in the search box
    • Look for "Claude Code for VS Code" by Anthropic
    • Verify it's the official extension (published by Anthropic)
  4. Install
    • Click the "Install" button
    • Wait for installation to complete
    • You may need to reload VS Code

💡 Visual Guide: The extension will appear in your Extensions sidebar. Look for the orange circular icon with a white star-like shape.

Step 2: Configure Your API Key

Setting Up the API Key

  1. Open Command Palette
    • Press Ctrl+Shift+P (Windows/Linux) or Cmd+Shift+P (Mac)
    • This opens the Command Palette
  2. Find API Key Command
    • Type "Claude Code: Set API Key"
    • Select the command from the dropdown
  3. Enter Your API Key
    • A prompt will appear asking for your API key
    • Paste your Anthropic API key (starts with "sk-ant-")
    • Press Enter to confirm
  4. Verify Configuration
    • Open Claude Code panel (see next step)
    • If configured correctly, you'll see the chat interface
    • If there's an error, check your API key and try again

⚠️ Security Note: Your API key is stored locally in VS Code settings. Never share your API key or commit it to version control. If you need to change it, use the same command palette command.

Step 3: Opening Claude Code Panel

Accessing Claude Code

  1. Find the Claude Icon
    • Look for the Claude Code icon in the Activity Bar (left sidebar)
    • It's an orange circular icon
  2. Open the Panel
    • Click the Claude Code icon
    • The Claude Code panel will open in the sidebar
  3. Alternative Method
    • Press Ctrl+Shift+P and type "Claude Code: Open"
    • Select "Claude Code: Open Chat"

Basic Usage

Starting a Conversation

Simply type your question or request in the chat input at the bottom of the Claude Code panel and press Enter.

Example prompts:

  • "Explain what this function does"
  • "Find all usages of this variable"
  • "Refactor this code to use async/await"

Understanding Your Codebase

Claude Code automatically reads your open files and project structure. You can explicitly ask it to analyze:

  • "Scan the entire project and explain the architecture"
  • "What are the main components of this codebase?"
  • "How does the authentication flow work?"

Code Editing

Claude Code can make edits to your code. When it suggests changes:

  1. Review the proposed changes
  2. Accept or reject individual edits
  3. Claude will explain what it's changing and why

Advanced Features

Multi-File Editing

Claude Code excels at making coordinated changes across multiple files:

User: "Add user authentication with JWT tokens"

Claude Code will:
- Create User model (models/user.js)
- Create auth middleware (middleware/auth.js)
- Update routes (routes/auth.js)
- Add dependencies to package.json
- Update environment configuration

Running Bash Commands

Claude Code can execute bash commands to help with development tasks:

  • "Run the tests and show me the results"
  • "Check what packages are installed"
  • "Show me the git status"

Note: Always review commands before execution. Claude will ask for confirmation for potentially destructive operations.

Code Reviews

Ask Claude Code to review your code for:

  • Security vulnerabilities
  • Performance issues
  • Code quality and best practices
  • Potential bugs
User: "Review the authentication module for security issues"

Claude Code analyzes:
- Password hashing implementation
- JWT token handling
- Session management
- Input validation
- SQL injection risks

Architectural Analysis

Get insights into your codebase architecture:

  • "Explain the overall architecture of this project"
  • "How do the different modules interact?"
  • "Suggest improvements to the code structure"

Practical Examples

Example 1: Adding a New Feature

Prompt:

"Add a user profile page that displays user information and allows editing name and email"

Claude Code will:

  • Create the profile component/view
  • Add route handling
  • Create API endpoints for fetching and updating user data
  • Update navigation to include profile link
  • Add form validation

Example 2: Debugging

Prompt:

"The API endpoint /api/users returns 500 error. Find and fix the issue"

Claude Code will:

  • Trace through the code execution path
  • Identify the error location
  • Explain what's causing the error
  • Propose a fix
  • Apply the fix after your confirmation

Example 3: Refactoring

Prompt:

"Refactor all callback-based functions to use async/await"

Claude Code will:

  • Find all callback-based functions in the codebase
  • Convert them to async/await syntax
  • Update all call sites
  • Ensure error handling is properly converted
  • Maintain code functionality throughout

Tips and Best Practices

✅ Be Specific in Your Requests

Instead of "improve this code," say "refactor this function to handle edge cases and add error handling."

✅ Review Changes Before Accepting

Always review Claude's proposed changes. It's very good, but human oversight ensures quality.

✅ Use Version Control

Commit your code before major changes. This makes it easy to revert if needed.

✅ Iterate and Refine

Have a conversation with Claude. Ask follow-up questions and refine your requests based on its suggestions.

✅ Monitor API Costs

Claude Code uses the Anthropic API. Monitor your usage in the Anthropic console to manage costs.

Troubleshooting

Extension not showing up
  • Reload VS Code (Ctrl+Shift+P → "Reload Window")
  • Check if the extension is enabled in Extensions view
  • Verify you have VS Code 1.80 or later
API key errors
  • Verify your API key at console.anthropic.com
  • Check that your API key is properly set (Command Palette → "Claude Code: Set API Key")
  • Ensure you have billing set up in your Anthropic account
  • Check your API usage limits
Claude not understanding my codebase
  • Make sure relevant files are open in VS Code
  • Explicitly ask Claude to "scan the project" or "read all files"
  • Provide context about your project structure
  • Break down complex requests into smaller parts

Ready to Transform Your Development Workflow?

Start using Claude Code in VS Code today and experience the power of AI-assisted coding.

Install Extension → Get API Key →