What Is an MCP Gateway? | FastMCP Pod: Summer School Ep. 1
An MCP gateway is one governed entry point that controls who can reach which MCP servers and which tools inside them. It's the API gateway pattern you already know, rebuilt for AI agents. Season 2 of the FastMCP Pod is Summer School: episodes that pin down the MCP terms everyone uses and nobody fully agrees on. First class in session — the MCP gateway. Jeremiah Lowin (Prefect founder, creator of FastMCP) and Radhika Gulati (Product Marketing Manager at Prefect) work through what a gateway actually is, why people keep confusing it with a registry, and where Prefect Horizon — Prefect's enterprise MCP gateway — fits the moment your team goes from one server to fifty. What you'll get: - A clean definition of "gateway," starting from the API gateway you already understand - Why a registry (discovery) and a gateway (governance) are useless without each other - Access control down to the individual tool, not just the server - How Horizon's Remix builds one governed endpoint out of tools from many servers - The MCP sprawl problem, leaked API keys, and what to do before it bites - Where the spec is heading: stateless servers and the new interceptors working group Chapters 00:00 Welcome to Summer School 00:53 What even is a gateway? 02:20 Why MCP needs one too 04:49 Gateway vs. registry (the thing people mix up) 05:47 Mapping the players: servers, registry, gateway 08:05 Access control, down to the individual tool 11:36 Horizon Remix: a virtual server from just the tools you need 12:22 MCP vs. CLI: individual habits vs. enterprise reality 14:09 What FastMCP handles vs. what a gateway handles 16:16 "We have MCP sprawl" — advice for teams 17:38 Leaked keys and supply-chain attacks 20:43 How Prefect runs gateways on itself 24:00 Where the spec is going: stateless 27:58 Interceptors and the future of gateways 29:20 MCP vs. CLI vs. API, the verdict 31:40 Wrap-up Start with FastMCP, scale with Horizon, try both free today: Horizon → prefect.io/horizon FastMCP → https://gofastmcp.com Got a term that's quietly confusing you? Drop it in the comments — we build the next class from your questions.