iTunes / Apple Music

Import playlists from an exported iTunes/Apple Music Library.xml — a static, local playlist source layered on top of the Filesystem provider. It works no matter which provider is active (Roon, Jellyfin, or any other), the same as the .m3u/.m3u8 discovery it rides alongside: this isn't a provider of its own, it's an extra playlist source the Filesystem provider owns and merges in.

Connecting

Export your library: in Music.app (macOS) or iTunes (Windows), File → Library → Export Library. This produces a Library.xml file wherever you save it.
Make sure that file is reachable inside the container (put it somewhere under your MUSIC_ROOT mount, or add a separate volume mount for it).
Set Administration → iTunes/Apple Music Library.xml path to that file's path (e.g. /music/Library.xml) — editable live, no restart.

What gets imported

Every user-created playlist in the library, including smart playlists (the exported file already holds their resolved track list, so no rule evaluation is needed on Trobar's side). The built-in per-media-type views iTunes always creates — Library, Music, Movies, TV Shows, Podcasts, Audiobooks, Purchased, Genius — are excluded; they aren't something you curated.

Tracks are matched against your local library the same way every other provider's playlists are: by the on-disk path recorded in Library.xml when it resolves under MUSIC_ROOT, tolerant of a differing mount prefix (the library was very likely exported from a different machine than the one running Trobar) — falling back to artist/album/title otherwise.

The one real limitation: it's a snapshot, not a live sync

Since macOS Catalina, Music.app no longer keeps Library.xml updated on its own — it's a point-in-time export, not something Trobar can watch for changes. If you add or edit playlists, re-export and overwrite the same file — Trobar re-reads it fresh on every sync (the same way it re-reads .m3u files), so the next sync picks up the change automatically. No re-import step, no restart.