Comment 6 for bug 1476290

Background: I'm working on a standalone service with a much more sophisticated domain model than currently used by Mixxx. Exporting tracks from Mixxx (including cue points and loops) is already implemented for testing purposes. As a consequence I'm neither interested in extending the existing Mixxx database schema nor to work on any integration tasks other than connecting Mixxx with aoide.

The OpenAPI spec should give you an impression of the requests and the underlying domain model. I've just renamed "TrackMarker" to "PositionMarker" recently as a response to your comment ;)
https://gitlab.com/uklotzde/aoide-rs/blob/development/resources/openapi.yaml

Most of the track metadata in the rekordbox XML file should be covered with slight variations. Currently only a single tempo is stored in aoide. I will extend this to support multiple tempo markers instead. The approach used by rekordbox is simple and straightforward, worth adopting.

Support for playlists is out of scope right now. I favor prepared queries (~ virtual/dynamic crates) instead. Prepared queries and their metadata can be stored as JSON in local files or external databases. Please also see the corresponding topic on Zulip:
https://mixxx.zulipchat.com/#narrow/stream/109171-development/topic/aoide.20Music.20Library

PS: A recent DJ TechTools article was the initiator to continue working towards this long term goal again.
https://djtechtools.com/2019/03/11/5-futuristic-dj-software-features-that-will-soon-be-commonplace/
"Share Libraries + Track Data Between Every Software"