The MCP TypeScript SDK is the official reference implementation for building Model Context Protocol servers and clients in TypeScript. It provides a complete, type-safe API for defining tools, resources, and prompts that AI assistants can discover and invoke. The SDK handles the protocol layer — message serialization, transport management, capability negotiation — so developers can focus on implementing the actual functionality their MCP server provides.
The SDK supports all three MCP transport types: stdio for local process communication (ideal for CLI tools and desktop apps), Server-Sent Events (SSE) for web-based integrations, and the newer Streamable HTTP transport that the March 2026 specification introduced as the preferred method for remote servers. Built-in authentication helpers simplify securing MCP endpoints, and the cross-runtime support (Node.js, Bun, Deno) means servers can be deployed in virtually any JavaScript environment.
With 12,100+ GitHub stars, this is the most widely used SDK in the MCP ecosystem and the foundation that hundreds of community MCP servers are built on. Whether you're building a database connector, a cloud service integration, or a specialized developer tool, the TypeScript SDK provides the standard building blocks with thorough documentation and examples from the official MCP organization.
