This plugin lets you send text or binary data in a UDP packet.
Do you want to make a little widget to put on your stream and have it controlled by a StreamDeck? Just make your widget listen for commands on a UDP port and use this plugin to send it commands. It can send text or raw bytes. I made a little death count tracker for a game and needed to send it single byte commands and was kind of surprised that there wasn't something like this already available. After a few ugly workarounds (like running echo|nc commands via Automator or Shortcuts), I decided to finally learn some node/javascript and see how hard it would be to make a plugin and got this working in a day. Simply pick the action you need (Bytes or Text) and set the host, port, and data. Since this is a very generic task that you will probably add to a few buttons, I recommend you make your own icons for them.
