For the major desktop and mobile platforms, messaging (push notifications) shall be supported by Qt. In this context, messaging is the ability to send messages locally on the device, and between devices, giving notifications about changed states etc. 

The API shall be cross-platform, exposing the same API on all platforms. The API should preferably leverage the native messaging system for the platform, e.g. https://firebase.google.com/docs/cloud-messaging/ for Android, APNs for macOS/iOS, and WNS for Windows. How to solve this for Linux and embedded Linux is something we need to look into.

This epic will collect all the user stories related to this kind of messaging, notifications and push notifications.

The priority order to support target OS with this Epic is

1. Mobile phones and tablets: Android, iOS
2. Desktop: Windows 10/11
3. Optional: Desktop: Linux, MacOS, Windows 8, Other
4. Optional: Embedded Linux, Other

Delivery through Marketplace

Instead of building this in to the Qt releases delivery train we should build this as an add-on / extension for Qt (Conan addon) and optionally enable distribution and possible also sales through Qt Marketplace.