Claude Code is Anthropic's CLI tool for AI-assisted software engineering. It operates directly in the terminal, reading and editing files, running commands, and integrating with external tools via MCP servers.

Key Features

• Terminal-native: no IDE required
• Direct file editing with diff-based review
• MCP server integration for external tools (Linear, Playwright, GA4, etc.)
• Hook system for pre/post tool execution (e.g., linting on file save)
• CLAUDE.md project files for persistent instructions
• Memory system for cross-session context

Configuration

Project instructions go in CLAUDE.md at the repo root. Per-user global instructions go in ~/.claude/CLAUDE.md. Memory files persist in ~/.claude/projects/<project>/memory/.

MCP Integration

Claude Code connects to MCP servers defined in ~/.claude.json or project-level .claude.json. Each server exposes tools that Claude Code can call during a session.

Example MCP servers used in this ecosystem:

• Playwright (browser automation and testing)
• Linear (project management)
• GA4 Analytics (Google Analytics reporting)
• Kubernetes (cluster management)

Related Blog Posts

• Claude Code + CodeRabbit: local AI code review before PR creation
• Playwright MCP: browser verification via MCP
• Cross-Tool AI Rules with Ruler: sharing instructions across Claude Code and other tools