You don’t actually have to create a group chat room in order to use whispers. You just need to:
-
Connect to one of the group chat servers
-
Issue the raw command
CAP REQ :twitch.tv/commandsto let the server know you want to receive data besides PRIVMSGs -
Listen for the WHISPER commands. Most clients/libraries that are not specifically designed for Twitch will need to be modified to support this command so I recommend watching the raw commands coming in over your connection to see how it needs to be parsed.