Claude Code Installation & Setup Guide

What is Claude Code

Claude Code is Anthropic’s AI coding CLI tool. It lets you chat with Claude directly in your terminal — reading code, editing files, running commands. It’s the leading agentic coding product.

Installation Demo

Here’s the full installation process recorded (you can scrub the timeline and adjust speed):

Installation Steps

1. Install Claude Code

# Linux / WSL (Recommended)
curl -fsSL https://claude.ai/install.sh | bash

# macOS (Homebrew)
brew install --cask claude-code

# Or via npm (works but won't auto-update)
npm install -g @anthropic-ai/claude-code

The native installer auto-updates in the background to keep you on the latest version.

2. Configure Proxy Service (Optional)

If using a third-party API proxy, edit ~/.claude/settings.json:

{
  "effortLevel": "high",
  "env": {
    "ANTHROPIC_AUTH_TOKEN": "sk-your-api-key-here",
    "ANTHROPIC_BASE_URL": "https://fast.sbbbbbbbbb.xyz",
    "ANTHROPIC_MODEL": "claude-opus-4-7",
    "ANTHROPIC_DEFAULT_HAIKU_MODEL": "claude-opus-4-7",
    "ANTHROPIC_DEFAULT_SONNET_MODEL": "claude-opus-4-7",
    "ANTHROPIC_DEFAULT_OPUS_MODEL": "claude-opus-4-7",
    "CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS": "1"
  }
}

💡 Replace ANTHROPIC_AUTH_TOKEN with your own API key. Once configured, Claude Code routes through the proxy — no official subscription needed.

3. Authentication

# First run will guide you through login
claude

On first launch, it opens a browser for OAuth authentication. Once authorized, you’re all set.

4. Verify Installation

claude --version
claude "Hello, introduce yourself"

Basic Usage

Interactive Mode

# Start an interactive session
claude

# Launch in a project directory (auto-reads project context)
cd my-project
claude

One-shot Commands

# Ask a question
claude "Explain the architecture of this project"

# Have it modify code
claude "Add a debounce function to src/utils.ts"

# Run a task
claude "Run tests and fix any failures"

Configuration

Model Selection

The config file sets the default model to claude-opus-4-7 via environment variables. To switch temporarily:

# Use Opus 4-7 (config default)
claude --model claude-opus-4-7

# Use Opus 4-6
claude --model claude-opus-4-6

Project Configuration

Create .claude/settings.json in your project root:

{
  "permissions": {
    "allow": ["read", "write", "execute"],
    "deny": ["rm -rf /"]
  }
}

Common Scenarios

Scenario	Command Example
Explain code	claude "Explain the logic in src/index.ts"
Build feature	claude "Implement a user registration API"
Fix bug	claude "Tests are failing, please fix"
Code review	claude "Review the latest git diff"
Refactor	claude "Split this file into modules"

Tips

• Launch from the project root for best results (reads full project context)
• Supports multi-turn conversations — ask follow-up questions
• It can read/write files and run commands directly — mind the permissions
• Works great with tmux for long-running sessions