I'm looking for a way to let external applications connect to the server that uses my plug-in and let those applications communicate with the plug-in. (Those external applications would be applications or minecraft mods that players can download and use that to do or view things on the server.) The most straightforward way would be to open a new ServerSocket and use that one, but that would require the host to open another port, which usually costs extra money or is not possible at all. That's why I am looking for a way to use the same ServerSocket that is being used by minecraft and then distinguish between normal player connections and special connections. This will most likely be a dirty job that requires reflection, but I would be ok with that. The problem is that I can't find where I should 'hack my way in'. Does anyone know where I should look? And I am also interested in alternative ways to accomplish this if anyone happens to have such an idea.