An ancient (but superior) technology called IRC (Internet Relay Chat). Fortunately, Twitch supports it. Unfortunately, Twitch doesn’t support all of it. See the Twitch Without the Twitch videos for how to use it.
I also use Weechat in my terminal, which provides a nice FIFO for communicating with IRC directly from any application running on the system simply with redirection of stdout. (But it’s not quite quick enough to read from without lag.)