MCP in Production

What's in the twelve chapters

Part 1 - Foundations

• Chapter 1. Why MCP, and what it actually is - the three primitives, the two transports, what MCP solved that Plugins and function-calling didn't. Free preview.
• Chapter 2. Anatomy of a server - stdio adapter, HTTP service, in-process embedded; the four architectural shapes a real server takes.
• Chapter 3. Building your first production-grade server - worked example, npm init through npm publish. Every chapter from here refers back.

Part 2 - Surface

• Chapter 4. Auth, secrets, and identity flow - the four common patterns, the LLM-vs-human identity problem, what to do when your upstream API doesn't fit.
• Chapter 5. Schema design, or how to not poison the model - the longest chapter. Naming, parameter modeling, the tool-list size problem (40,000 tokens is not OK).
• Chapter 6. Tools that compose - output-shape-as-input-shape, pagination, list-then-detail, idempotency, cross-server composition.
• Chapter 7. Error handling that the model can act on - throw discipline, trigger phrases, transient vs terminal retry, a six-axis grading rubric.

Part 3 - Lifecycle

• Chapter 8. Testing a probabilistic consumer - unit, integration, and end-to-end testing patterns when the consumer is non-deterministic; the harness pattern that makes E2E tolerable.
• Chapter 9. Hosting, scaling, and not going broke on idle - six realistic options, an honest comparison of managed MCP platforms, container packaging, reproducible builds off your laptop.
• Chapter 10. Security review survival - the threat model, the mitigations, the questions a competent reviewer will ask, a checklist you can run yourself.

Part 4 - In practice

• Chapter 11. Case studies from the @yawlabs portfolio - tailscale-mcp (the first one), npmjs-mcp (auth-shaped), aws-mcp (schema-shaped), lemonsqueezy-mcp (errors and money). Architecture, surprises, what a v2 would look like.
• Chapter 12. What's next, and what to bet on - in-flight spec changes, ecosystem gaps, and the bets I'd make today.

Who it's for

You ship code for a living. You have read the MCP spec and shipped at least one server. You know what tools/list and notifications/initialized are without looking them up. You want to know why your aws-mcp tool list is 40,000 tokens and what to do about it.

You're somewhere between mid and senior on the IC ladder, or a tech lead deciding how to invest your team's MCP work.

Not for: spec walkthroughs (modelcontextprotocol.io does that better), "what is MCP" introductions, or vendor-neutral tool surveys.

Companion volume

MCP in Production is Volume I of the Yaw Labs Production Series. Volume II, Claude Code in Production, covers the operator side - running the agent that calls these servers. Together they bracket the agentic-tooling stack: the builder's view of MCP and the operator's view of Claude Code.

What's in the box

• The book in PDF and EPUB.
• Free updates as the MCP spec evolves and the @yawlabs servers ship new lessons.
• Read Chapter 1 free at mcp.hosting/mcp-in-production.
• Pointers into the live @yawlabs/* server repositories the book references.