Claude Code Tutorials & Guides

Claude Code is Anthropic's official command-line interface for Claude. It brings AI-assisted coding directly into your terminal — letting you write, edit, debug, and refactor code through natural language while Claude reads your actual project files and runs commands.

What is Claude Code?

Unlike a chat interface where you paste code snippets back and forth, Claude Code is an agentic coding tool. It can:

• Read and edit files directly in your project
• Run shell commands and see their output
• Search your codebase with grep and glob
• Create and manage files across your repository
• Connect to external tools via MCP (Model Context Protocol)

Installation

Claude Code requires Node.js 18+ and an Anthropic API key.

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

# Verify installation
claude --version

# Start a session in your project directory
cd your-project
claude

Essential Commands

Command	What it does
claude	Start an interactive session in current directory
claude "task description"	Run a one-shot task and exit
claude --continue	Resume the most recent session
claude --model claude-opus-4-8	Use a specific model
/help	Show available slash commands inside a session
/compact	Summarise context to save tokens
/cost	Show token usage and cost for the session

Key Features

• File-aware context — Claude reads your actual source code, not just what you paste
• Tool use — Read, Edit, Write, Bash, Grep, Glob built in
• MCP support — Connect Claude to databases, APIs, and external services
• CLAUDE.md — Project-specific instructions Claude reads on every session
• Hooks — Run shell scripts automatically before/after tool use
• Permission modes — Control which actions Claude can take autonomously

Use Cases

• Refactor a legacy codebase with AI guidance
• Write tests for untested functions
• Debug complex errors by letting Claude trace through files
• Build new features from a natural-language spec
• Automate repetitive code tasks (rename, migrate, format)