MCP TypeScript SDK: Build AI Tool Servers with Node.js

The MCP TypeScript SDK is the official library for building MCP servers and clients in the JavaScript/TypeScript ecosystem. It handles protocol compliance, transport management, and serialization, letting you focus on building great tools.

Overview

The SDK provides both server and client implementations, supporting stdio and HTTP/SSE transports. It includes TypeScript-first APIs with full type safety, making it easy to build reliable MCP integrations.

Key Features

• Full TypeScript Support — Type-safe APIs for servers and clients
• Multiple Transports — stdio, HTTP/SSE out of the box
• Schema Validation — Automatic JSON Schema validation for tool inputs
• Streaming Support — Handle long-running operations with progress updates
• Express Integration — Mount MCP servers in Express.js applications

Getting Started

npm install @modelcontextprotocol/sdk

import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";

const server = new McpServer({ name: "my-server", version: "1.0.0" });
const transport = new StdioServerTransport();
await server.connect(transport);

Use Cases

• Node.js Tool Servers — Build tools that leverage the npm ecosystem
• Web API Bridges — Connect web APIs to AI agents via MCP
• Full-Stack Integration — MCP servers as part of Express/Next.js apps
• Browser Tools — Puppeteer/Playwright-based web interaction tools

Best Practices

• Use Zod for validation — Leverage Zod schemas for runtime type checking
• Implement graceful shutdown — Handle SIGINT/SIGTERM for clean cleanup
• Log structured data — Use JSON logging for production debugging
• Bundle for distribution — Use esbuild/tsup for single-file distribution

Frequently Asked Questions

Conclusion

Stay ahead of the curve by exploring our comprehensive directories. Browse the AI Agent directory with 400+ agents and the MCP Server directory with 2,300+ servers to find the perfect tools for your workflow.