A developer‑focused guide on implementing the Model Context Protocol (MCP) as a cloud‑hosted tooling layer for LLM apps. Grounded in a working implementation we built and deployed; includes tuning notes, metrics, and pitfalls.

- Why MCP vs. bespoke adapters - Architecture (gateway + small Python services) - Runtime loop (pause/execute/resume) - Budgets, timeouts, retries, circuit breakers - Security/governance (least privilege, audit) - Observability (latency/error metrics) - Examples (RAG chat, CRM triage, doc indexing) - Migration tips