@mhoye oh did you see that systemd 257 announced a new focus on an API to replace its own use of dbus, called varlink?
https://lwn.net/SubscriberLink/1002398/d8e7bd4a6107e0a7/
https://lwn.net/Articles/742675/ (from 2018, earlier announcement)
> Poettering noted¹ that one might say that documentation for sd-json and sd-varlink is ""barely existing"", but there are examples of using them within the systemd source tree.