Claude Code CLI: Installation, Usage, and Why AI Coding Tools Matter

AI coding assistants aren’t just a trend—they’re reshaping how we write, debug, and understand code. Claude Code CLI brings Anthropic’s Claude AI directly to your terminal, making it an essential tool for modern developers. It is my goto tool when it comes to AI pair programming because of its feature set, speed and its compatibility with various models.

In this guide, we’ll cover:

• Installing Claude Code CLI (Linux focus)
• Basic usage
• Practical examples
• Why AI coding tools matter now more than ever

Note: Claude Code CLI supports various Anthropic-compatible models including GLM and MiniMax. We’ll cover how to configure these models in upcoming posts!

What is Claude Code CLI?

Claude Code CLI is Anthropic’s agentic coding tool that lives in your terminal, acting as an AI pair programmer that can:

• Analyze codebases instantly
• Generate and refactor code from descriptions
• Debug issues with AI-powered insights
• Explain complex code in simple terms
• Handle git workflows automatically
• Write tests and documentation
• Execute routine tasks through natural language

Think of it as having a senior developer available 24/7, right in your terminal.

Prerequisites

Before installing Claude Code CLI:

1. Node.js 18+ installed
2. API key from console.anthropic.com
3. Terminal access use wsl if on Windows

Installation

We’ll use npm for installation:

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

# Verify installation
claude --help

Configuration

Setting Up Your API Key

# Set API key as environment variable
export ANTHROPIC_API_KEY="your-api-key-here"

Configuration File

You can create a settings file for advanced configuration:

# Create config directory
mkdir -p ~/.config/claude

# Example settings.json
cat > ~/.config/claude/settings.json << 'EOF'
{
  "model": "claude-sonnet-4-5",
  "spinnerTipsEnabled": true,
  "statusLine": {
    "enabled": true,
    "format": " | "
  }
}
EOF

Basic Usage

Launch Claude Code

# Start interactive session
claude

# Launch with custom settings
claude --settings ~/.config/claude/settings.json

# Enable debug mode
claude --debug

Inside Claude Code: Slash Commands

Once you’re in the Claude Code terminal, you can use slash commands:

# Get help with available commands
/help

# Switch AI model
/model

# Check API usage and costs
/cost

# Check context usage
/context

# Check memory management
/memory

# Clear conversation history
/clear

# Undo code changes to previous state
/rewind

# Validate configuration and diagnose issues
/doctor

# Add directory to context
/add-dir src/components

# Manage MCP servers
/mcp

# Compact conversation to reduce context
/compact

Practical Examples

Example 1: Code Review

Inside Claude Code terminal:

> "Review my changes and suggest improvements"

Example 2: Bug Fixing

Inside Claude Code terminal:

> "Debug this error: The application crashes on startup"

Example 3: Code Generation

Inside Claude Code terminal:

> "Create a Python function to calculate fibonacci numbers with tests"

Example 4: Git Workflow

Inside Claude Code terminal:

> "Commit my changes and create a PR"

Best Practices

1. Be Specific

Instead of:

> "Create a python function"

Say:

> "Create a robust Python function to calculate fibonacci numbers that handles edge cases"

2. Review All Changes

Claude will always show you proposed changes before applying them. Always review carefully:

> "Show me the changes before applying them"

3. Use Context Management

Check and manage your context usage:

# Check current context
/context

# Add specific directories to context
/add-dir src/components

# Compact conversation when needed
/compact

4. Enable Thinking Mode

Toggle thinking mode to see Claude’s reasoning:

> "Press Tab to toggle thinking mode"

This helps you understand Claude’s approach to solving problems.

5. Use @ to Reference Files

In interactive mode, use @ to reference specific files:

> "Review @src/utils/helper.js and optimize it"
> "Explain @config/database.ts"
> "Fix all bugs in @controllers/user.js"

This helps Claude understand exactly which files you’re referring to.

Why AI Coding Tools Matter

AI coding tools like Claude Code CLI are transforming software development:

1. Democratizing access to expert knowledge - Anyone can learn best practices and understand complex algorithms instantly
2. Boosting productivity - Handling repetitive and complex tasks faster than ever
3. Improving code quality - Catching security vulnerabilities, and enforcing best practices in real-time
4. Reducing memorization - No need to memorize syntax or APIs
5. Anyone can code - Non-experts can build functional applications, and domain experts can implement ideas without deep coding knowledge
6. Future-proofing skills - Shifting focus from syntax to problem-solving