Strange notification behavior with Home Assistant App

I have a weird situation going on. I just installed the official mobile app for Android on my phone and my wife’s phone. I didn’t set up any cloud connection, Duck DNS, VPN, or anything else. I didn’t give the app any external access IP address. My plan was to just use the app for notifications when we are home and on the home network (which is when we mostly need them currently), and then the few notifications I need when we are away are set to come from an email sent by Home Assistant to my phone (converted into a text message).

The notifications at home via the app have been working well, and they are significantly more timely than the emails sent to my phone number as texts. That’s the good news. Here’s where it gets weird: somehow my wife and I are now receiving notifications through the app even when we are NOT home and NOT on the home network. How is that even possible? I have confirmed that the app itself doesn’t work when I am in a different location as I never gave it an external IP address. I’m guessing this means I have some sort of issues with a port being open on my router, but I haven’t checked that yet. Even with that possibility, however, it seems odd that I am able to receive notifications from the Home Assistant app remotely despite the fact that I can’t actually connect remotely to Home Assistant using the app and I never set up any of the external access stuff.

Any thoughts and help would be appreciated! Thank you!

I think this goes through Google servers.

see the article here.

https://thexplorion.com/android-push-notifications-work/

As I understand this, device is know to HA, HA sends to google, google sends to your phone. This happens at home or away. I believe you can stop notifications on the app.

Thank you! I clearly missed that part of the documentation. It makes me feel much better about what is going on.

Thank you! The description from a programming standpoint of what goes on with notifications was very interesting. It definitely helped me understand what is happening.