Just FYI, in go, global variables (and functions, types, etc) are package-global, not file-global. Thus, TAG here will be defined in all of the files in server/. I'm assuming you probably want something more like `COMMAND_TAG` as above.

Also, you don't /really/ need constants for these. I mean, what else would the command prefix be? (You also assume that it's `/` in a bunch of later places)