[zorr]

Using the Spotify Rest API it is already possible to build nice feature rich Spotify clients for remote players. I don't think there is a supported native playback library? I'm not sure how local playback is implemented in this project.

The main problem I have with the Spotify API is that its remote playback management API is limited/incompatible with some players (Sonos).

[kraxarn]

It relies on a separate client for playback, which can be an open source client like librespot/spotifyd, or an official client. It's also mostly older systems using the older, deprecated, playback client that aren't compatible with the Web API afaik.