FastMCP 4 shipped on the stateless protocol, so we ran a live session on the question underneath it: how to build an MCP server worth shipping. Curation over 1:1 mapping, measured token bloat, middleware, code mode, plugins, evals, and deployment.
FastMCP 4 is stable and generally available, with support for the new MCP 2026-07-28 protocol: stateless requests, interactive tools, background tasks, extensions, and more. Old clients keep working.
Auth is the part of MCP people complain about most. We work through the difference between authentication and authorization, why local servers never needed either, and how MCP's auth story went from miserable to workable.
