They use intercom's Fin AI. Probably powered by a Sonnet or Opus model.

That said, it can't handle legal/refund/complicated requests and just forwards to a human for those

Support is probably the last place AI will be used end to end. There will always need to be a human in there somewhere.

AI is very good at "deflecting" support tickets ATM but rubbish at actual support tickets (source I work in the industry)