Mcp Ts Core

A TypeScript framework for building MCP servers, not a server itself. You install it as a dependency and use its declarative builders to define tools, resources, and prompts with Zod schemas. The framework handles transports (stdio, HTTP), auth (JWT, OAuth), storage backends, OpenTelemetry tracing, and graceful shutdown. Two standout features: enrichment contracts that automatically populate both structuredContent and content arrays so Claude Code and Claude Desktop both get context, and typed error contracts where you declare failure modes upfront and the linter checks your handler against them. Runs on Bun, Node, and Cloudflare Workers. Reach for this when you want to build domain logic without writing plumbing code.