Am considering Hubitat after having already delved into HomeSeer this past month.
Ideally if there were a current app for integrating AT&T Digital Life, I would certainly use it. But apart from that, and perhaps this might be a general question on already installed door sensors, is there any way I can leverage existing alarm door sensors in Hubitat? My AT&T system uses the external magnet sensors. So can sensors be integrated to communicate with two different hubs?
Generally speaking, the answer is no for the actual devices. You need something like what @Keo posted to link the hubs themselves.
If you’re not necessarily planning to keep your AT&T subscription, it’s possible the sensors could be paired with the HE hub. What’s the actual brand/model # of the door sensors?