There are two kinds of MCP server, they solve different problems, and almost nothing tells you which one you are building until you are deep enough in to have already made the wrong choice. I worked this out from a submission form. More on that below, because it turns out to be the clearest signal in the whole ecosystem and it is buried in a footnote. The two shapes Local (stdio). The server runs as a process on the user's own machine. The client — Claude Desktop, Cursor, wh...