I am wondering if there is a chat program that works locally when the internet is out but still be connected to from the internet. I know this will be something that is self hosted.
Bonus points if I can set it up on the raspberry pi that is running Home Assistant.
Not a lot but we have used it. It’s beta quality. You need to be in Bluetooth range if there’s no internet - and it works. Good for tent-to-tent texting.