Root cause of zero LB recommendations (every similar-recordings AND
similar-artists call returned HTTP 404, worker logs):
- Wrong host/path: client called
api.listenbrainz.org/1/explore/similar-{recordings,artists}/{mbid}.
/explore/... is a WEBSITE route, not an API endpoint — it 308s then
404s. Similarity datasets live on the separate Labs API.
- Invalid algorithm: the hardcoded
session_…_session_30_…_limit_100_filter_True_… is not a permitted
Labs enum member (400s) regardless of host.
Verified against the live Labs API:
GET labs.api.listenbrainz.org/similar-recordings/json
?recording_mbids=<mbid>&algorithm=<algo>
GET labs.api.listenbrainz.org/similar-artists/json
?artist_mbids=<mbid>&algorithm=<algo>
algorithm=session_based_days_9000_session_300_contribution_5_threshold_15_limit_50_skip_30
→ 200 for both. Response field names (recording_mbid/artist_mbid/
name/score) already match the existing structs — parsing unchanged.
- Add defaultLabsBaseURL + Client.LabsBaseURL (separate from the main
BaseURL; scrobble submission still uses api.listenbrainz.org).
- Drop the count/limit query param — result size is encoded in the
algorithm name (limit_50); caller still applies its own top-K.
- Tests: newTestClient sets LabsBaseURL; the two *_LimitParamSet tests
become *_MbidParamSet (assert the Labs path + mbid query param).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
- similarity.Worker batch 5→25 (tracks AND artists per 1h tick). At
5/h a freshly-scrobbled library took days to build a usable
similarity pool; 25/h converges in hours, still well under
ListenBrainz rate limits (429 aborts the tick).
- scanrun Stage 2b track backfill now runs unbounded (-1) instead of
reusing the album backfill's 5000 staged cap. It's a one-time
whole-library heal with no progress UI; a cap just left tracks.mbid
partially NULL (3634/18056 after one pass) until several future
scans caught up, re-reading untagged files each time. One uncapped
pass converges; later scans only re-read the remaining NULL rows.
Album backfill keeps its 5000 cap (it has staged scan_runs UX).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
upsertArtistSimilar keeps the existing matched path (top-K rows into
artist_similarity) and adds a parallel unmatched-persist loop with the
same top-K cap. Empty-name rows are skipped — we can't render a
suggestion card without a name. Logs unmatched-side errors at WARN
without aborting the tick (mirrors the matched-path policy).
Replace stub with full tickOnce: drains played tracks/artists via
ListPlayedTracksNeedingSimilarity / ListPlayedArtistsNeedingSimilarity,
calls LB SimilarRecordings/SimilarArtists, filters to local library via
bulk MBID lookup, enforces top-K=20 by score, and upserts similarity
rows. 429 aborts the entire tick; other errors log-and-skip. Ten
integration tests covering no-op, library filtering, top-K cap, 7-day
freshness cap, stale refresh, 429 abort, transient skip, and artist
pass.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
bvandeusen