MCP — Model Context Protocol

Model Context Protocol (MCP) is an open standard that lets Claude connect to external tools and data sources in a consistent, permission-controlled way. It powers everything from filesystem access to database queries to custom business integrations.

In This Section

What is MCP

Protocol overview — why MCP exists, what problem it solves, and how it differs from raw function calling.

MCP Architecture

Hosts, clients, servers, and transports (stdio and SSE) — how the protocol layers fit together.

Using MCP with Claude Desktop

Connecting MCP servers in the Claude.ai desktop app — config file, adding servers, and testing connections.

Using MCP with Claude Code

MCP in the Claude Code CLI — adding, enabling, and managing servers in your project config.

Popular MCP Servers

Filesystem, GitHub, Postgres, Brave Search, Puppeteer, Slack — the most useful ready-to-use servers.

Building a Custom MCP Server

SDK walkthrough — expose any tool or data source to Claude by writing your own MCP server.