Getting Started with Claude Code CLI¶

Welcome! This tutorial will get you from zero to your first terminal session with Claude Code CLI.

What You'll Learn¶

What Claude Code CLI is (and how it differs from web Claude)
How to install the CLI tool
How to start your first terminal session
Understanding the command-line interface

What is Claude Code CLI?¶

Claude Code CLI is a terminal-based AI assistant that runs directly in your command line. This is different from the Claude web interface (claude.ai) - here's why it matters:

Claude Web	Claude Code CLI
Runs in browser	Runs in your terminal
Copy/paste code	Direct file access
Describe your project	Sees your actual files
Chat only	Executes real commands
Isolated	Integrated with your tools

With Claude Code CLI, you can:

See your files - Read any file in your project directory
Edit your code - Make changes directly to files on disk
Run commands - Execute shell commands and see real output
Search codebases - Find functions, patterns, and dependencies
Use git - Create commits, branches, and pull requests

Think of it as having a senior developer in your terminal who can actually touch your code.

Installation¶

Prerequisites¶

Node.js 18 or higher

# Check your version
node --version

# Should show v18.x.x or higher

A terminal - Terminal.app, iTerm2, Windows Terminal, or any shell
Authentication - Either:
Anthropic API key, or
Claude Pro/Max subscription

Install Claude Code CLI¶

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

Verify installation:

claude --version

You should see version output like claude-code v1.x.x.

Your First Terminal Session¶

Starting the CLI¶

Open your terminal (Terminal.app, iTerm2, Windows Terminal, etc.) and type:

claude

The first time you run this, you'll be prompted to authenticate. Follow the on-screen instructions in your terminal.

The Terminal Interface¶

Once started, you'll see something like this in your terminal:

╭─────────────────────────────────────────╮
│ Claude Code                             │
│ Working directory: /your/current/path   │
╰─────────────────────────────────────────╯

>

The > is your input prompt. Type your message and press Enter. All interaction happens right here in the terminal - no browser needed.

Your First Conversation¶

Try these starter prompts:

> What files are in this directory?

Claude will look at your current folder and describe what's there.

> Create a simple hello.py file that prints "Hello, World!"

Claude will create the file for you. Check your directory - it's really there!

> Run hello.py

Claude will execute the file and show you the output.

Exiting¶

To end your session: - Type /exit or - Press Ctrl+C twice

Key Concepts¶

The Working Directory¶

Claude Code CLI operates in whatever directory you started it from in your terminal. It can see and modify files in that directory and its subdirectories - just like any other CLI tool.

# Navigate to your project first
cd ~/my-project

# Then start Claude Code CLI
claude

This is why Claude Code CLI is powerful - it has the same file access as you do in that terminal session.

Conversations Have Memory¶

Within a terminal session, Claude remembers what you've discussed. You can say things like: - "Actually, change that function to..." - "Add error handling to what you just wrote" - "Undo that last change"

Tool Permissions¶

Claude Code CLI asks permission in the terminal before taking certain actions: - Creating or modifying files - Running shell commands - Accessing the network

You'll see prompts like:

Claude wants to create file: hello.py
Allow? (y/n)

Type y and press Enter to approve, or n to deny.

Try It Yourself¶

Exercise 1: Hello Claude¶

Create a new directory:

mkdir claude-practice
cd claude-practice

Start Claude Code:
```
claude
```
Ask Claude to:
Create a Python file that prints your name
Run the file
Modify it to also print today's date
Exit Claude Code and verify the file exists:
```
cat *.py
```

Common Issues¶

"command not found: claude"¶

npm's global bin directory isn't in your PATH. Try:

# Find where npm installs global packages
npm config get prefix

# Add to your PATH (in ~/.bashrc or ~/.zshrc)
export PATH="$PATH:$(npm config get prefix)/bin"

Authentication Failed¶

Make sure you've either: - Set the ANTHROPIC_API_KEY environment variable, or - Completed the login flow for Claude Pro/Max

Permission Denied¶

If you see permission errors during install:

# Use npx instead
npx @anthropic-ai/claude-code

What's Next?¶

Now that you can start Claude Code CLI and have a conversation in your terminal, let's learn the essential commands in 02-basic-commands.

Summary: - Claude Code CLI is a terminal-based AI assistant (different from claude.ai web) - Install with npm install -g @anthropic-ai/claude-code - Start with claude command, exit with /exit or Ctrl+C - It works in your current directory and has real file/command access - All interaction happens in the terminal - no browser needed

Learning Resources¶

Featured Video¶

NetworkChuck: AI in the Terminal (3.6M subscribers, 500K+ views)

Comprehensive tutorial covering Claude Code installation, setup, and first steps. Perfect for beginners learning AI coding assistants from the command line. Includes Gemini CLI and ChatGPT comparisons.

Additional Resources¶

Type	Resource	Description
🎬 Video	Claude Code Beginners Guide 2025	All About AI - Complete walkthrough for beginners
📚 Official Docs	Claude Code Getting Started	Anthropic's official documentation
📖 Tutorial	DataCamp Claude Code Tutorial	Hands-on guide with practical examples
🎓 Free Course	Anthropic Academy	Official free courses with certificates
💼 Commercial	Complete AI Coding Course 2025	Udemy - Cursor, Claude Code comprehensive