My home assistant setup is super simple: pre-configured Home Assistant Green box, Zigbee dongle and some assorted Zigbee devices scattered around my home. I have the Home Assistant app on my phone to see the Dashboard while I’m at home, but since I never configured the box to be accessible from outside of my network, I obviously can’t see the Dashboard if I’m not at home. Very basic stuff so far.

A few weeks ago, I built a little automation. I shoved a vibration sensor into my doorbell box (it’s one of those that uses an electric motor to hit an actual bell) and when it detects the doorbell ringing, it flickers my light and sends a notification that says “ding dong” to my phone. The purpose is just to hear the doorbell ring when I have headphones on. The lights work perfectly fine, the notification is a bit delayed sometimes because I probably don’t give the App enough permissions to hang out in the background all the time. I’ve never felt like fixing it though, since the lights are good enough by themselves.

Now I’m on my first longer trip since setting up that automation and I’ve noticed that I occasionally get the “dong dong” notification on my phone. First few times I’ve ignored it, because I assumed it’s just old notifications that got queued while I was home but didn’t fire until the app was allowed to sync. But the notifications started coming in at way too reasonable times and I checked in with my husband at home – turns out they’re actually completely correct and I’m getting actual real-time notifications for the doorbell ringing.

But like - how?! I thought my Home Assistant Green box isn’t set up to send anything to the outside world?! I can’t see my dashboard from other networks, so why would notifications be any different? Does anyone have any ideas as to why I’m getting those notifications?

edit: Thought it would make sense to include a screenshot of my settings; As you see, my home assistant URL is a local IP address. I have no idea why my phone would be able to talk to that? It can’t talk to my local-IP-only Jellyfin server either, so why would this be any different?