Claude Code by Anthropic | AI Coding Agent, Terminal, IDE

# Claude Code Docs > Official documentation for Claude Code, Anthropic's agentic coding tool available in the terminal, IDE, desktop app, and browser. Covers installation, configuration, skills, subagents, hooks, MCP, the Agent SDK, and reference material. ## Docs - [How the agent loop works](https://code.claude.com/docs/en/agent-sdk/agent-loop.md): Understand the message lifecycle, tool execution, context window, and architecture that power your SDK agents. - [Use Claude Code features in the SDK](https://code.claude.com/docs/en/agent-sdk/claude-code-features.md): Load project instructions, skills, hooks, and other Claude Code features into your SDK agents. - [Track cost and usage](https://code.claude.com/docs/en/agent-sdk/cost-tracking.md): Learn how to track token usage, deduplicate parallel tool calls, and calculate costs with the Claude Agent SDK. - [Give Claude custom tools](https://code.claude.com/docs/en/agent-sdk/custom-tools.md): Define custom tools with the Claude Agent SDK's in-process MCP server so Claude can call your functions, hit your APIs, and perform domain-specific operations. - [Rewind file changes with checkpointing](https://code.claude.com/docs/en/agent-sdk/file-checkpointing.md): Track file changes during agent sessions and restore files to any previous state - [Intercept and control agent behavior with hooks](https://code.claude.com/docs/en/agent-sdk/hooks.md): Intercept and customize agent behavior at key execution points with hooks - [Hosting the Agent SDK](https://code.claude.com/docs/en/agent-sdk/hosting.md): Deploy and host Claude Agent SDK in production environments - [Connect to external tools with MCP](https://code.claude.com/docs/en/agent-sdk/mcp.md): Configure MCP servers to extend your agent with external tools. Covers transport types, tool search for large tool sets, authentication, and error handling. - [Migrate to Claude Agent SDK](https://code.claude.com/docs/en/agent-sdk/migration-guide.md): Guide for migrating the Claude C