MCP TypeScript SDK (V2) / @modelcontextprotocol/server

@modelcontextprotocol/server

The MCP (Model Context Protocol) TypeScript server SDK. Build MCP servers that expose tools, resources, and prompts.

WARNING

This is a beta release. The API surface is settling but breaking changes remain possible until v2 stabilizes. Please try it and open issues — feedback during the beta directly shapes the stable release.

NOTE

This is v2 of the MCP TypeScript SDK. It replaces the monolithic @modelcontextprotocol/sdk package from v1. See the migration guide if you're coming from v1.

Install

npm install @modelcontextprotocol/server@beta

TypeScript ≥6.0 no longer auto-includes @types/* — add "types": ["node"] to your tsconfig.json compilerOptions (the published .d.mts references Buffer).

Optional framework adapters: @modelcontextprotocol/express, @modelcontextprotocol/hono, @modelcontextprotocol/node.

Documentation

• Repository README — overview, package layout, examples
• Server guide — tools, resources, prompts, and the rest of the server surface
• Serving guide — stdio, HTTP, the framework adapters, sessions, and authorization
• API reference
• MCP specification

Modules

• fromJsonSchema
• index
• server/completable
• server/completable.examples
• server/createMcpHandler
• server/invoke
• server/legacyInputRequiredShim
• server/listenRouter
• server/mcp
• server/mcp.examples
• server/middleware/hostHeaderValidation
• server/middleware/hostHeaderValidation.examples
• server/middleware/originValidation
• server/perRequestTransport
• server/requestStateCodec
• server/server
• server/serverEventBus
• server/serveStdio
• server/stdio
• server/stdio.examples
• server/streamableHttp
• server/streamableHttp.examples
• shimsNode
• shimsWorkerd
• stdio
• validators/ajv
• validators/cfWorker