There's ntfy. I'm not sure if that will fit your bill or not.
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I tried it recently and while I love it for my notifications, I was disappointed to see I can send text from my PC to my phone but not the other way around using the android app. Or there's something I'm doing wrong.
KDE connect is the only similar one I'm aware of. I'm surprised it didn't work well for you, but I've personally never tried it with Mac
I'm awaiting parts for a new PC build so I'll definitely try it again with a different OS.
I have actually been trying to use KDEConnect with my media center under Gnome using GSConnect for mouse and keyboard. In that case I have found it unstable. Works for awhile, then says unreachable. Should work great but does not.
Found XMouse, and MultiVNC way better for my use. The just work. So not a true connectivity problem. Something about KDEConnect/GSConnect.
It's not FOSS, but have you tried Join? It was basically created as a response to Pushbullet pulling their paywall stunt, so most disgruntled PB users switched to Join. It's made by the same guy who maintains Tasker btw, joaomgcd.
I did actually, right around that time iirc. I want to say it wasn't very well done at the start but I could be mistaken. Might have to give it another look. Thanks!
My understanding is that you're not going to find a self hosted solution that makes use of SMS (not counting email to SMS gateways) because sending SMS programmatically requires a SMS gateway those aren't cheap (think of Twilio). You can find many options for app-based notifications (push notifications usually) and email-based notifications as a workaround.
Fair. And I'm willing to pay, even if it's open source and it's via contributing. PB irked me because they put some of the previously free stuff behind a paywall so the value went down in my mind. That said, it worked very well.
As far as I know sending and receiving SMS through KDE connect, I'm using the gnome implementation Gsconnect, should work flawlessly. Not the prettiest experience but it works. GSconnect comes with a message viewer that even let's you browse old SMS