MCP TypeScript SDK

MCP

MCPGitHubLevel: IntermediateFree

MCP TypeScript SDK

4.0/52dm rating

Suited to web teams working with Node.js.

The official library for writing MCP servers and clients in TypeScript / Node.js.

Official site How to use it

Overview

The MCP TypeScript SDK is the official set of libraries for building MCP servers and clients in TypeScript. From v2, the SDK is split into separate packages: @modelcontextprotocol/server for building servers and @modelcontextprotocol/client for building clients, plus optional middleware packages for Node, Express, Fastify and Hono.

The main branch is currently v2, the stable release implementing the MCP 2026-07-28 specification. The SDK runs on Node.js, Bun and Deno; servers support stdio and Streamable HTTP, with authentication helpers. Schemas for tools and prompts use the Standard Schema spec, so you can choose Zod v4, Valibot or ArkType.

The v1.x branch (the @modelcontextprotocol/sdk package) continues to receive bug and security fixes for at least six months after the v2 release date, so existing projects have time to migrate.

Highlights

Clearly separated packages

server and client are independent packages; install only what you need.

Middleware for web frameworks

Ready-made integration packages for Node, Express, Fastify and Hono.

Multi-runtime

Supports Node.js, Bun and Deno.

Flexible schema library

Uses Standard Schema, compatible with Zod v4, Valibot and ArkType.

Authentication support

Includes server-side auth helpers and client-side OAuth.

Clear upgrade path

A guide for moving from v1 to v2; v1.x remains supported for a while.

What it's for

Add MCP to an existing backend

Businesses using Express or Hono attach an MCP server to their current API.

Expose web app data to AI

Let an AI assistant read orders and appointments from a system written in Node.js.

Build tools for the engineering team

Write a local stdio server so AI can help with operations on a project.

Be a client inside a product

Your application connects on its own to external MCP servers.

Run on edge or Deno

Deploy lightweight servers on modern runtimes.

How to use it

1
Install the server package
Install the server package with npm (or the equivalent bun add, deno add).
$npm install @modelcontextprotocol/server
2
Install the client package if needed
Only install it when your application needs to connect to other MCP servers.
$npm install @modelcontextprotocol/client
3
Choose middleware
If you use Express, install the integration package along with express.
$npm install @modelcontextprotocol/express express
4
Write your first server
Follow the first-server guide in the repo's docs folder or the v2 documentation.
5
Upgrade from v1
Projects using @modelcontextprotocol/sdk should read the migration guide to v2.

Video guides

The Ultimate MCP Crash Course - Build From Scratch
Web Dev Simplified

Build your first MCP Server in TypeScript
Roy Derks

Build a Real-world MCP Server with One TypeScript File Full Tutorial
Nader Dabit

Real-world example

Illustrative scenario

A spa services company in Hanoi has a booking system written in Node.js and Express. The developer installs @modelcontextprotocol/server with the Express middleware package, and creates a tool to look up free slots and a resource describing the service list. Receptionists use an AI assistant to check open time slots when customers phone in, instead of opening several screens.

Tips & notes

Use v2 for new projects
v2 is the stable branch on main and follows the latest specification.
Install only the packages you need
Splitting server, client and middleware keeps the application lean.
Standardize on one schema library
Pick one library such as Zod v4 for the whole project for easier maintenance.
Plan to leave v1
v1.x is guaranteed fixes for only a minimum of six months after the v2 release date.