diff --git a/backend/migrations/034_ops_upstream_error_events.sql b/backend/migrations/034_ops_upstream_error_events.sql
new file mode 100644
index 00000000..f8bfa5e2
--- /dev/null
+++ b/backend/migrations/034_ops_upstream_error_events.sql
@@ -0,0 +1,9 @@
+-- Add upstream error events list (JSONB) to ops_error_logs for per-request correlation.
+--
+-- This is intentionally idempotent.
+
+ALTER TABLE ops_error_logs
+    ADD COLUMN IF NOT EXISTS upstream_errors JSONB;
+
+COMMENT ON COLUMN ops_error_logs.upstream_errors IS
+    'Sanitized upstream error events list (JSON array), correlated per gateway request (request_id/client_request_id); used for per-request upstream debugging.';