fix: use group_by instead of find_many(distinct) in /tag/list to avoid full table scan

litellm/proxy/management_endpoints/tag_management_endpoints.py

@@ -26,7 +26,6 @@
 )
 from litellm.proxy.management_helpers.utils import handle_budget_for_entity
 from litellm.types.tag_management import (
-    LiteLLM_DailyTagSpendTable,
     TagConfig,
     TagDeleteRequest,
     TagInfoRequest,
@@ -445,25 +444,30 @@ async def list_tags(
             list_of_tags.append(tag_dict)
 
         ## QUERY DYNAMIC TAGS ##
-        dynamic_tags = await prisma_client.db.litellm_dailytagspend.find_many(
-            distinct=["tag"],
+        # Use group_by instead of find_many(distinct=["tag"]).
+        # Prisma's distinct fetches all columns for all rows and deduplicates
+        # in application code, which is extremely slow on large tables.
+        # See: https://www.prisma.io/docs/orm/prisma-client/queries/aggregation-grouping-summarizing#distinct-under-the-hood
+        dynamic_tag_rows = await prisma_client.db.litellm_dailytagspend.group_by(
+            by=["tag"],
+            where={"tag": {"not": None}},
+            # The old find_many(distinct=...) returned arbitrary timestamps from
+            # whichever row Prisma happened to pick. MIN/MAX give more meaningful
+            # values: earliest appearance and most recent activity.
+            _min={"created_at": True},
+            _max={"updated_at": True},
         )
 
-        dynamic_tags_list = [
-            LiteLLM_DailyTagSpendTable(**dynamic_tag.model_dump())
-            for dynamic_tag in dynamic_tags
-        ]
-
         dynamic_tag_config = [
             {
-                "name": tag.tag,
+                "name": row["tag"],
                 "description": "This is just a spend tag that was passed dynamically in a request. It does not control any LLM models.",
                 "models": None,
-                "created_at": tag.created_at.isoformat(),
-                "updated_at": tag.updated_at.isoformat(),
+                "created_at": row.get("_min", {}).get("created_at").isoformat() if row.get("_min", {}).get("created_at") else None,
+                "updated_at": row.get("_max", {}).get("updated_at").isoformat() if row.get("_max", {}).get("updated_at") else None,
             }
-            for tag in dynamic_tags_list
-            if tag.tag not in stored_tag_names
+            for row in dynamic_tag_rows
+            if row["tag"] not in stored_tag_names
         ]
 
         return list_of_tags + dynamic_tag_config

tests/test_litellm/proxy/management_endpoints/test_tag_management_endpoints.py

@@ -244,6 +244,133 @@ async def test_delete_tag():
         app.dependency_overrides.clear()
 
 
+@pytest.mark.asyncio
+async def test_list_tags_with_dynamic_tags():
+    """
+    Test that list_tags uses group_by to get distinct dynamic tags efficiently
+    and merges them with stored tags, excluding duplicates.
+    """
+    from datetime import datetime
+    from unittest.mock import AsyncMock, Mock
+
+    from litellm.proxy.auth.user_api_key_auth import user_api_key_auth
+
+    mock_user_auth = UserAPIKeyAuth(
+        user_id="test-user-123",
+        user_role=LitellmUserRoles.PROXY_ADMIN,
+    )
+    app.dependency_overrides[user_api_key_auth] = lambda: mock_user_auth
+
+    try:
+        with patch("litellm.proxy.proxy_server.prisma_client") as mock_prisma:
+            mock_db = Mock()
+            mock_prisma.db = mock_db
+
+            # Setup stored tags
+            stored_tag = Mock()
+            stored_tag.tag_name = "stored-tag"
+            stored_tag.description = "A stored tag"
+            stored_tag.models = ["model-1"]
+            stored_tag.model_info = {}
+            stored_tag.spend = 0.0
+            stored_tag.budget_id = None
+            stored_tag.created_at = datetime(2025, 1, 1)
+            stored_tag.updated_at = datetime(2025, 1, 1)
+            stored_tag.created_by = "user-123"
+            stored_tag.litellm_budget_table = None
+            mock_db.litellm_tagtable.find_many = AsyncMock(return_value=[stored_tag])
+
+            # Setup dynamic tags via group_by — includes one that overlaps with stored
+            mock_db.litellm_dailytagspend.group_by = AsyncMock(return_value=[
+                {"tag": "dynamic-tag-1", "_min": {"created_at": datetime(2025, 2, 1)}, "_max": {"updated_at": datetime(2025, 3, 1)}},
+                {"tag": "dynamic-tag-2", "_min": {"created_at": datetime(2025, 2, 2)}, "_max": {"updated_at": datetime(2025, 3, 2)}},
+                {"tag": "stored-tag", "_min": {"created_at": datetime(2025, 1, 1)}, "_max": {"updated_at": datetime(2025, 1, 1)}},  # duplicate, should be excluded
+            ])
+
+            headers = {"Authorization": "Bearer sk-1234"}
+            response = client.get("/tag/list", headers=headers)
+
+            assert response.status_code == 200
+            result = response.json()
+
+            # Should have 1 stored + 2 dynamic (the duplicate excluded)
+            assert len(result) == 3
+
+            tag_names = [t["name"] for t in result]
+            assert "stored-tag" in tag_names
+            assert "dynamic-tag-1" in tag_names
+            assert "dynamic-tag-2" in tag_names
+
+            # Verify dynamic tags include created_at/updated_at
+            dynamic_tags = {t["name"]: t for t in result if t["name"].startswith("dynamic-")}
+            assert dynamic_tags["dynamic-tag-1"]["created_at"] is not None
+            assert dynamic_tags["dynamic-tag-1"]["updated_at"] is not None
+
+            # Verify group_by was used instead of find_many(distinct=...)
+            mock_db.litellm_dailytagspend.group_by.assert_called_once_with(
+                by=["tag"],
+                where={"tag": {"not": None}},
+                _min={"created_at": True},
+                _max={"updated_at": True},
+            )
+    finally:
+        app.dependency_overrides.clear()
+
+
+@pytest.mark.asyncio
+async def test_list_tags_no_dynamic_tags():
+    """
+    Test list_tags when there are no dynamic tags in the spend table.
+    """
+    from datetime import datetime
+    from unittest.mock import AsyncMock, Mock
+
+    from litellm.proxy.auth.user_api_key_auth import user_api_key_auth
+
+    mock_user_auth = UserAPIKeyAuth(
+        user_id="test-user-123",
+        user_role=LitellmUserRoles.PROXY_ADMIN,
+    )
+    app.dependency_overrides[user_api_key_auth] = lambda: mock_user_auth
+
+    try:
+        with patch("litellm.proxy.proxy_server.prisma_client") as mock_prisma:
+            mock_db = Mock()
+            mock_prisma.db = mock_db
+
+            stored_tag = Mock()
+            stored_tag.tag_name = "stored-tag"
+            stored_tag.description = "A stored tag"
+            stored_tag.models = []
+            stored_tag.model_info = None
+            stored_tag.spend = 0.0
+            stored_tag.budget_id = None
+            stored_tag.created_at = datetime(2025, 1, 1)
+            stored_tag.updated_at = datetime(2025, 1, 1)
+            stored_tag.created_by = "user-123"
+            stored_tag.litellm_budget_table = None
+            mock_db.litellm_tagtable.find_many = AsyncMock(return_value=[stored_tag])
+
+            mock_db.litellm_dailytagspend.group_by = AsyncMock(return_value=[])
+
+            headers = {"Authorization": "Bearer sk-1234"}
+            response = client.get("/tag/list", headers=headers)
+
+            assert response.status_code == 200
+            result = response.json()
+            assert len(result) == 1
+            assert result[0]["name"] == "stored-tag"
+
+            mock_db.litellm_dailytagspend.group_by.assert_called_once_with(
+                by=["tag"],
+                where={"tag": {"not": None}},
+                _min={"created_at": True},
+                _max={"updated_at": True},
+            )
+    finally:
+        app.dependency_overrides.clear()
+
+
 @pytest.mark.asyncio
 async def test_get_deployments_by_model_id():
     """