jackal VS Gotify

Take your pick. Or just look here.

XMPP servers have the ability to use backend authenticators that can share existing auth infrastructure. This is commonly used for LDAP integration at corporations, for instance. The jackal XMPP server, since it is in Go and this is /r/golang, appears to have some support for this although it appears you'd have to go learn GRPC, the docs basically assume you know what you're doing with that already.

How much traffic do you expect ? If you don't expect much traffic and you are happy with single server (or maybe a sharded cluster) you may be able to pull something off by yourself. Otherwise you should go with something already proved, like XMPP. Have a look at https://github.com/ortuman/jackal

Raw sockets are just a "plain pipes" that can carry any logic, while XMPP is already well defined, long established protocol for instant messaging. Check it out: - XMPP Server - XMPP client lib

jackal

I use apprise with Gotify

You can self-host a notification service using https://gotify.net/ for example, but you may need to ask the user to disable battery usage restrictions if you don't want the OS to kill the background process.

If you do not need the state tracking, but instead need something that can deliver push notifications to you, check out ntfy and gotify

Gotify (version 2.5.1): A client for receiving push notifications

I've found Gotify to work well for that

Just FYI - there's also shoutrrr and gotify with similar functionality. I've tried them, they're very good, but not fitting my (very humble) needs.