Add API for other apps to show locations on the map

Hej, first things first: I am grateful that there is a maps app for NextCloud. But IMHO it could be a lot more useful if other apps could provide locations to show in the Maps app. For example the contacts app has the ability to show contacts from other sources (not only the contacts in the app itself and from the Mail app).

My use case is, that we have a lot of facilities that we manage in an own app. It would be nice if we could view them in the Maps app. Currently we could provide them via the Contacts app but there is no way to show only our facilities.

Is there any way to add this feature? Or any point to start off so I could add this feature by myself? As it is an API endpoint I guess there should be some thoughts about the definition of the endpoint.

Start by reviewing the Maps app's existing data interfaces and comparing them with how the Contacts app exposes locations from other sources. Define an API contract that lets external apps provide locations and identify how facilities could be shown separately. Done means the endpoint and its integration expectations are documented and usable by another app.