diff --git a/internal/db/dbq/models.go b/internal/db/dbq/models.go
index e7b7e229..5ce88a32 100644
--- a/internal/db/dbq/models.go
+++ b/internal/db/dbq/models.go
@@ -29,6 +29,14 @@ type Artist struct {
 	UpdatedAt pgtype.Timestamptz
 }
 
+type ArtistSimilarity struct {
+	ArtistAID pgtype.UUID
+	ArtistBID pgtype.UUID
+	Score     float64
+	Source    string
+	FetchedAt pgtype.Timestamptz
+}
+
 type ContextualLike struct {
 	ID            pgtype.UUID
 	UserID        pgtype.UUID
@@ -129,6 +137,14 @@ type Track struct {
 	UpdatedAt   pgtype.Timestamptz
 }
 
+type TrackSimilarity struct {
+	TrackAID  pgtype.UUID
+	TrackBID  pgtype.UUID
+	Score     float64
+	Source    string
+	FetchedAt pgtype.Timestamptz
+}
+
 type User struct {
 	ID                  pgtype.UUID
 	Username            string
diff --git a/internal/db/dbq/similarity.sql.go b/internal/db/dbq/similarity.sql.go
new file mode 100644
index 00000000..5a92cecf
--- /dev/null
+++ b/internal/db/dbq/similarity.sql.go
@@ -0,0 +1,191 @@
+// Code generated by sqlc. DO NOT EDIT.
+// versions:
+//   sqlc v1.27.0
+// source: similarity.sql
+
+package dbq
+
+import (
+	"context"
+
+	"github.com/jackc/pgx/v5/pgtype"
+)
+
+const getArtistsByMBIDs = `-- name: GetArtistsByMBIDs :many
+SELECT id, mbid FROM artists WHERE mbid = ANY($1::text[])
+`
+
+type GetArtistsByMBIDsRow struct {
+	ID   pgtype.UUID
+	Mbid *string
+}
+
+func (q *Queries) GetArtistsByMBIDs(ctx context.Context, dollar_1 []string) ([]GetArtistsByMBIDsRow, error) {
+	rows, err := q.db.Query(ctx, getArtistsByMBIDs, dollar_1)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var items []GetArtistsByMBIDsRow
+	for rows.Next() {
+		var i GetArtistsByMBIDsRow
+		if err := rows.Scan(&i.ID, &i.Mbid); err != nil {
+			return nil, err
+		}
+		items = append(items, i)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return items, nil
+}
+
+const getTracksByMBIDs = `-- name: GetTracksByMBIDs :many
+SELECT id, mbid FROM tracks WHERE mbid = ANY($1::text[])
+`
+
+type GetTracksByMBIDsRow struct {
+	ID   pgtype.UUID
+	Mbid *string
+}
+
+// Bulk in-library lookup: maps a slice of MBIDs back to local track IDs.
+func (q *Queries) GetTracksByMBIDs(ctx context.Context, dollar_1 []string) ([]GetTracksByMBIDsRow, error) {
+	rows, err := q.db.Query(ctx, getTracksByMBIDs, dollar_1)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var items []GetTracksByMBIDsRow
+	for rows.Next() {
+		var i GetTracksByMBIDsRow
+		if err := rows.Scan(&i.ID, &i.Mbid); err != nil {
+			return nil, err
+		}
+		items = append(items, i)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return items, nil
+}
+
+const listPlayedArtistsNeedingSimilarity = `-- name: ListPlayedArtistsNeedingSimilarity :many
+SELECT DISTINCT ar.id, ar.mbid
+FROM artists ar
+JOIN tracks t ON t.artist_id = ar.id
+JOIN play_events pe ON pe.track_id = t.id
+WHERE ar.mbid IS NOT NULL
+  AND NOT EXISTS (
+      SELECT 1 FROM artist_similarity asim
+      WHERE asim.artist_a_id = ar.id
+        AND asim.source = 'listenbrainz'
+        AND asim.fetched_at > now() - interval '7 days'
+  )
+ORDER BY ar.id
+LIMIT $1
+`
+
+type ListPlayedArtistsNeedingSimilarityRow struct {
+	ID   pgtype.UUID
+	Mbid *string
+}
+
+func (q *Queries) ListPlayedArtistsNeedingSimilarity(ctx context.Context, limit int32) ([]ListPlayedArtistsNeedingSimilarityRow, error) {
+	rows, err := q.db.Query(ctx, listPlayedArtistsNeedingSimilarity, limit)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var items []ListPlayedArtistsNeedingSimilarityRow
+	for rows.Next() {
+		var i ListPlayedArtistsNeedingSimilarityRow
+		if err := rows.Scan(&i.ID, &i.Mbid); err != nil {
+			return nil, err
+		}
+		items = append(items, i)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return items, nil
+}
+
+const listPlayedTracksNeedingSimilarity = `-- name: ListPlayedTracksNeedingSimilarity :many
+SELECT DISTINCT t.id, t.mbid
+FROM tracks t
+JOIN play_events pe ON pe.track_id = t.id
+WHERE t.mbid IS NOT NULL
+  AND NOT EXISTS (
+      SELECT 1 FROM track_similarity ts
+      WHERE ts.track_a_id = t.id
+        AND ts.source = 'listenbrainz'
+        AND ts.fetched_at > now() - interval '7 days'
+  )
+ORDER BY t.id
+LIMIT $1
+`
+
+type ListPlayedTracksNeedingSimilarityRow struct {
+	ID   pgtype.UUID
+	Mbid *string
+}
+
+// Tracks with at least one play, an MBID, and no fresh listenbrainz row
+// (no row at all, OR fetched_at older than 7 days). Used by the worker
+// to find work each tick. Bounded by $1.
+func (q *Queries) ListPlayedTracksNeedingSimilarity(ctx context.Context, limit int32) ([]ListPlayedTracksNeedingSimilarityRow, error) {
+	rows, err := q.db.Query(ctx, listPlayedTracksNeedingSimilarity, limit)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var items []ListPlayedTracksNeedingSimilarityRow
+	for rows.Next() {
+		var i ListPlayedTracksNeedingSimilarityRow
+		if err := rows.Scan(&i.ID, &i.Mbid); err != nil {
+			return nil, err
+		}
+		items = append(items, i)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return items, nil
+}
+
+const upsertArtistSimilarity = `-- name: UpsertArtistSimilarity :exec
+INSERT INTO artist_similarity (artist_a_id, artist_b_id, score, source, fetched_at)
+VALUES ($1, $2, $3, 'listenbrainz', now())
+ON CONFLICT (artist_a_id, artist_b_id, source)
+DO UPDATE SET score = EXCLUDED.score, fetched_at = EXCLUDED.fetched_at
+`
+
+type UpsertArtistSimilarityParams struct {
+	ArtistAID pgtype.UUID
+	ArtistBID pgtype.UUID
+	Score     float64
+}
+
+func (q *Queries) UpsertArtistSimilarity(ctx context.Context, arg UpsertArtistSimilarityParams) error {
+	_, err := q.db.Exec(ctx, upsertArtistSimilarity, arg.ArtistAID, arg.ArtistBID, arg.Score)
+	return err
+}
+
+const upsertTrackSimilarity = `-- name: UpsertTrackSimilarity :exec
+INSERT INTO track_similarity (track_a_id, track_b_id, score, source, fetched_at)
+VALUES ($1, $2, $3, 'listenbrainz', now())
+ON CONFLICT (track_a_id, track_b_id, source)
+DO UPDATE SET score = EXCLUDED.score, fetched_at = EXCLUDED.fetched_at
+`
+
+type UpsertTrackSimilarityParams struct {
+	TrackAID pgtype.UUID
+	TrackBID pgtype.UUID
+	Score    float64
+}
+
+func (q *Queries) UpsertTrackSimilarity(ctx context.Context, arg UpsertTrackSimilarityParams) error {
+	_, err := q.db.Exec(ctx, upsertTrackSimilarity, arg.TrackAID, arg.TrackBID, arg.Score)
+	return err
+}
diff --git a/internal/db/queries/similarity.sql b/internal/db/queries/similarity.sql
new file mode 100644
index 00000000..15a76b58
--- /dev/null
+++ b/internal/db/queries/similarity.sql
@@ -0,0 +1,50 @@
+-- name: ListPlayedTracksNeedingSimilarity :many
+-- Tracks with at least one play, an MBID, and no fresh listenbrainz row
+-- (no row at all, OR fetched_at older than 7 days). Used by the worker
+-- to find work each tick. Bounded by $1.
+SELECT DISTINCT t.id, t.mbid
+FROM tracks t
+JOIN play_events pe ON pe.track_id = t.id
+WHERE t.mbid IS NOT NULL
+  AND NOT EXISTS (
+      SELECT 1 FROM track_similarity ts
+      WHERE ts.track_a_id = t.id
+        AND ts.source = 'listenbrainz'
+        AND ts.fetched_at > now() - interval '7 days'
+  )
+ORDER BY t.id
+LIMIT $1;
+
+-- name: ListPlayedArtistsNeedingSimilarity :many
+SELECT DISTINCT ar.id, ar.mbid
+FROM artists ar
+JOIN tracks t ON t.artist_id = ar.id
+JOIN play_events pe ON pe.track_id = t.id
+WHERE ar.mbid IS NOT NULL
+  AND NOT EXISTS (
+      SELECT 1 FROM artist_similarity asim
+      WHERE asim.artist_a_id = ar.id
+        AND asim.source = 'listenbrainz'
+        AND asim.fetched_at > now() - interval '7 days'
+  )
+ORDER BY ar.id
+LIMIT $1;
+
+-- name: GetTracksByMBIDs :many
+-- Bulk in-library lookup: maps a slice of MBIDs back to local track IDs.
+SELECT id, mbid FROM tracks WHERE mbid = ANY($1::text[]);
+
+-- name: GetArtistsByMBIDs :many
+SELECT id, mbid FROM artists WHERE mbid = ANY($1::text[]);
+
+-- name: UpsertTrackSimilarity :exec
+INSERT INTO track_similarity (track_a_id, track_b_id, score, source, fetched_at)
+VALUES ($1, $2, $3, 'listenbrainz', now())
+ON CONFLICT (track_a_id, track_b_id, source)
+DO UPDATE SET score = EXCLUDED.score, fetched_at = EXCLUDED.fetched_at;
+
+-- name: UpsertArtistSimilarity :exec
+INSERT INTO artist_similarity (artist_a_id, artist_b_id, score, source, fetched_at)
+VALUES ($1, $2, $3, 'listenbrainz', now())
+ON CONFLICT (artist_a_id, artist_b_id, source)
+DO UPDATE SET score = EXCLUDED.score, fetched_at = EXCLUDED.fetched_at;