fix(spend): register the benchmarks route and the session rollup's retention

Three CI gates caught the same class of omission: this PR adds a new member to
an enumerated set, and each set has a registry or a test that enumerates it.

The benchmarks route was reachable on the monolithic app but present in neither
component allowlist, so it would have 404'd on both the gateway and the backend
pod. It is an admin read over the rollup, so it belongs on the backend, next to
the adaptive-router routes it sits beside in the dashboard.

The retention cleanup gained a fourth table, which moved two call counts the
spend-log cleanup tests assert on. Those tests now also assert that the new
table is actually pruned and that it is keyed on last activity, so the count is
backed by a claim about behaviour rather than standing alone.

The rollup's cleanup log line built its message eagerly instead of passing the
count as a %-style argument

backend/routes/allowlist.py

@@ -44,6 +44,7 @@ BACKEND_PATH_PREFIXES: tuple[str, ...] = (
     "/router/",
     "/router_settings",
     "/adaptive_router/",
+    "/auto_router/",
     "/fallback",
     "/fallbacks",
     "/cache_settings",

litellm/proxy/db/db_transaction_queue/spend_log_cleanup.py

@@ -258,7 +258,7 @@ class SpendLogCleanup:
             verbose_proxy_logger.info("Deleted %s expired tool index rows", index_deleted)
 
             sessions_deleted = await self._delete_old_auto_router_sessions(prisma_client, cutoff_date)
-            verbose_proxy_logger.info(f"Deleted {sessions_deleted} expired auto-router session rollups")
+            verbose_proxy_logger.info("Deleted %s expired auto-router session rollups", sessions_deleted)
 
         except Exception as e:
             # .exception() captures the traceback; str(e) alone on a Prisma/DB

tests/test_litellm/proxy/test_spend_log_cleanup.py

@@ -158,8 +158,8 @@ async def test_cleanup_old_spend_logs_batch_deletion():
     mock_db = MagicMock()
 
     # Mock execute_raw to return deleted counts (3 spend-log batches, then the
-    # tool-index cleanup's first batch returning 0)
-    mock_db.execute_raw = AsyncMock(side_effect=[1000, 500, 0, 0])
+    # first batch of each derived table's cleanup returning 0)
+    mock_db.execute_raw = AsyncMock(side_effect=[1000, 500, 0, 0, 0])
 
     # Wire up mocks
     mock_prisma_client.db = mock_db
@@ -179,7 +179,7 @@ async def test_cleanup_old_spend_logs_batch_deletion():
     await cleaner.cleanup_old_spend_logs(mock_prisma_client)
 
     # Validate batching and deletion via raw SQL
-    assert mock_db.execute_raw.call_count == 4
+    assert mock_db.execute_raw.call_count == 5
 
     # Check the first call argument
     call_args_sql = mock_db.execute_raw.call_args_list[0][0][0]
@@ -193,6 +193,12 @@ async def test_cleanup_old_spend_logs_batch_deletion():
     tool_index_sql = mock_db.execute_raw.call_args_list[3][0][0]
     assert 'DELETE FROM "LiteLLM_SpendLogToolIndex"' in tool_index_sql
 
+    # So do the auto-router session rollups, keyed on last activity rather than
+    # session start so a live conversation is not pruned while still being written to
+    session_sql = mock_db.execute_raw.call_args_list[4][0][0]
+    assert 'DELETE FROM "LiteLLM_AutoRouterSession"' in session_sql
+    assert "last_turn_at" in session_sql
+
     # The LiteLLM_DailyToolSpend rollup must outlive spend-log retention: it is
     # the only copy of tool spend history once its per-request sources expire,
     # so spend-log cleanup must never touch it.
@@ -316,7 +322,7 @@ async def test_cleanup_uses_delete_when_not_partitioned():
     from unittest.mock import AsyncMock, MagicMock
 
     mock_prisma_client = MagicMock()
-    mock_prisma_client.db.execute_raw = AsyncMock(side_effect=[10, 0, 0])
+    mock_prisma_client.db.execute_raw = AsyncMock(side_effect=[10, 0, 0, 0])
 
     partition_manager = MagicMock()
     partition_manager.is_partitioned = AsyncMock(return_value=False)
@@ -335,7 +341,7 @@ async def test_cleanup_uses_delete_when_not_partitioned():
     await cleaner.cleanup_old_spend_logs(mock_prisma_client)
 
     partition_manager.drop_partitions_older_than.assert_not_awaited()
-    assert mock_prisma_client.db.execute_raw.await_count == 3
+    assert mock_prisma_client.db.execute_raw.await_count == 4
     delete_sql = mock_prisma_client.db.execute_raw.call_args_list[0][0][0]
     assert 'DELETE FROM "LiteLLM_SpendLogs"' in delete_sql