Building MCP Servers with Node.js and TypeScript

MCP servers let agents call your business capabilities with explicit contracts instead of fragile screen-scraping. In Node.js and TypeScript, treat each tool as a narrow API surface with typed inputs and predictable errors.

Structure

Separate transport (stdio or HTTP), tool registration and domain services. Domain logic should not depend on MCP SDK types—test it like any other service layer.

Permissions

Tools must enforce the same authorization rules as your REST API. An agent is just another client.

Versioning

When tool schemas change, bump versions and keep backward-compatible aliases during migration windows.

Operational concerns

Log tool latency, rate-limit expensive operations and return actionable error messages models can reason about.