Running the server

sqlmc mcp

sqlmc comes with the installer and is also a standalone download; see the CLI reference, §1. A client that was already running when you installed will not see the new PATH, so name the full path in its entry: %LOCALAPPDATA%\SqlMulticast\current\sqlmc.exe for the installer, or wherever you extracted the zip (the Microsoft Store version of the app does not include sqlmc). An update to the installed app stops a running sqlmc mcp, and the client has to start it again.

Transport is stdio. The server runs until stdin closes — that is how the client says it is done, and there is no other shutdown signal on this transport.

stdout is JSON-RPC and nothing else. Every log line, and anything a human might read, goes to stderr. This is not a style preference: a single stray write to stdout does not produce a warning or a wrong answer, it desynchronizes the framing and the session stops working, in a way that reads to the caller as the tool being broken.