Claude Code Setup

Claude Code is an AI coding assistant CLI from Anthropic.

Prerequisites

• Node.js 18+
• Anthropic API key (or Anthropic account for OAuth)

Step 1: Install

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

Step 2: Authenticate

Option A: OAuth via Claude Max (recommended)

claude login

This opens a browser for OAuth authentication. Uses your Claude Max subscription — no per-token billing.

Credentials stored in ~/.claude/.credentials.json.

Option B: API Key

export ANTHROPIC_API_KEY="your-api-key"

Pay-per-token via Anthropic API.

Step 3: Run

# Interactive mode
claude
 
# With initial prompt
claude "explain this code"
 
# In specific directory
claude --cwd /path/to/project

Configuration

Global Config

Located at ~/.claude.json:

{
  "permissions": {
    "allow": ["Bash", "Read", "Write", "Edit"],
    "deny": []
  },
  "mcpServers": {
    "obsidian": {
      "command": "npx",
      "args": ["@mauricio.wolff/mcp-obsidian@latest", "/path/to/vault"]
    }
  }
}

Project Config

Create CLAUDE.md in project root with instructions:

# CLAUDE.md
 
## Project Overview
This is a Node.js API server...
 
## Rules
- Use TypeScript
- Follow existing code style
- Run tests before committing

Claude reads this file automatically.

MCP Servers

MCP (Model Context Protocol) extends Claude with custom tools.

Add to ~/.claude.json:

{
  "mcpServers": {
    "server-name": {
      "command": "npx",
      "args": ["mcp-package-name", "arg1", "arg2"]
    }
  }
}

Directory Structure

~/.claude/
├── .credentials.json # OAuth tokens (if using claude login)
├── cache/            # Cached data
├── projects/         # Project metadata
├── todos/            # Task lists
├── history.jsonl     # Conversation history
└── stats-cache.json  # Usage statistics

Useful Commands

In the Claude CLI:

• /help — Show help
• /clear — Clear conversation
• /compact — Summarize conversation to save context
• /cost — Show token usage

Tips

• Use CLAUDE.md to give Claude project context
• Add MCP servers for specialized tools
• Claude remembers conversation until you /clear
• Works best with specific, clear instructions