@modelcontextprotocol/server and @modelcontextprotocol/client packages — FastMCP handles the protocol plumbing so you can focus on what your server actually does.
FastMCP 1.0 speaks both MCP protocol generations: the 2025 legacy era and the 2026-07-28 modern era. A server serves both at once, and a client negotiates one. Protocol eras installs that model, and every concept page builds on it.
The three pillars
Servers
Turn TypeScript functions into MCP tools, resources, and prompts — with middleware, auth, and composition.
Clients
Connect to one or many MCP servers, call tools, and wire LLM sampling to Anthropic, OpenAI, or Google with one line.
Apps
Build interactive UIs rendered directly in MCP host conversations using a server-side component library.
Get going
Quickstart
Build, run, and call your first MCP server in a few minutes.
CLI
Run, inspect, call, and install servers from the command line with
fastmcp.