@maiyannah Then !XMPP is exactly what you want. Personally I offer automagic account logins to anyone on #quitter.is and #quitter.es with an authentication module for #prosody that just piggybacks !GNUsocial's user table. So anyone on those servers can log in with their GS credentials :)
Authentication module including sample config: https://social.umeahackerspace.se/attachment/59391