diff --git a/supabase/migrations/20260611000000_claim_songstats_backfill_rows.sql b/supabase/migrations/20260611000000_claim_songstats_backfill_rows.sql
new file mode 100644
index 0000000..bfacdb8
--- /dev/null
+++ b/supabase/migrations/20260611000000_claim_songstats_backfill_rows.sql
@@ -0,0 +1,25 @@
+-- Atomic claim function for the Songstats backfill worker (recoupable/chat#1791).
+-- FOR UPDATE SKIP LOCKED can't be expressed through supabase-js, so the worker
+-- claims its batch via this RPC: pending rows in value order (rank_score DESC),
+-- marked in_progress and returned in one statement. Concurrent workers skip
+-- each other's locked rows instead of blocking.
+--
+-- SECURITY INVOKER (default): RLS on songstats_backfill_queue has no policies,
+-- so only the service-role worker (which bypasses RLS) can claim rows; anon /
+-- authenticated callers get zero rows even if they can execute the function.
+
+CREATE OR REPLACE FUNCTION claim_songstats_backfill_rows(batch_size integer)
+RETURNS SETOF songstats_backfill_queue
+LANGUAGE sql
+AS $$
+  UPDATE songstats_backfill_queue q
+  SET status = 'in_progress', updated_at = now()
+  WHERE q.id IN (
+    SELECT id FROM songstats_backfill_queue
+    WHERE status = 'pending'
+    ORDER BY rank_score DESC
+    FOR UPDATE SKIP LOCKED
+    LIMIT batch_size
+  )
+  RETURNING q.*;
+$$;