[chrismorgan]

That sounds to be exactly what the Push API (https://w3c.github.io/push-api/) is for the web: code can ask the user agent, “please give me a push endpoint”, and the UA gives it a URL, and then the code sends that URL to its backend server, which can then push to that endpoint, and messages will end up back at the user agent and be handed to the relevant code. On desktop platforms, Firefox defaults to using a Mozilla-operated push service, but on Android it could in theory use FCM, or Samsung’s equivalent, &c. if they supported the API.

I really don’t understand why mobile OSes don’t just adopt the Push API wholesale. Android especially. It’s such a mess having each app do its own thing and then have all kinds of problems with power saving measures; why not instead let the OS declare the push service to use (Google phones use FCM, Samsung phones use a Samsung push service, &c.), and apps just use what they’re given?