fix(proxy): count when a grouped log page starts past the last one

An out-of-range cursorless page returns nothing, and reading its total off the
offset reported more sessions than exist (page 4 of 100 sessions at page size 50
claimed 150). Only a page that holds rows, or the first page, ends the list;
anything past it falls back to the bounded count.

Claude-Session: https://claude.ai/code/session_01ESi9JwaXDww1vP3Qsrr4Mz

litellm/proxy/spend_tracking/spend_management_endpoints.py

@@ -2979,9 +2979,10 @@ async def _ui_session_grouped_spend_logs(
     by its newest non-MCP row, enriched by ``_build_ui_spend_logs_response``
     exactly like the flat listing, and the response carries
     ``next_session_cursor`` / ``has_more`` while ``total`` counts sessions
-    (capped like the flat total). A page that runs out of sessions is itself
-    the end of the list, so its ``total`` is ``offset + len(page)`` and the
-    grouped count query is skipped.
+    (capped like the flat total). A page that runs out of sessions while still
+    holding some is itself the end of the list, so its ``total`` is
+    ``offset + len(page)`` and the grouped count query is skipped; a page that
+    starts past the end says nothing about the total, so that one is counted.
     """
     where_clause: Final = " AND ".join(sql_conditions) if sql_conditions else "TRUE"
     cmp_op: Final = "<" if sort_desc else ">"
@@ -3026,7 +3027,8 @@ async def _ui_session_grouped_spend_logs(
         else None
     )
 
-    page_ends_the_list: Final = cursor is None and page_limit > 0 and not has_more
+    page_starts_inside_the_list: Final = offset == 0 or len(page_rows) > 0
+    page_ends_the_list: Final = cursor is None and page_limit > 0 and not has_more and page_starts_inside_the_list
     total_records, total_is_capped = (
         (offset + len(page_rows), False)
         if page_ends_the_list

tests/test_litellm/proxy/spend_tracking/test_spend_management_endpoints.py

@@ -6839,6 +6839,41 @@ async def test_ui_view_spend_logs_group_by_session_short_page_totals_itself(clie
         app.dependency_overrides.pop(ps.user_api_key_auth, None)
 
 
+@pytest.mark.asyncio
+async def test_ui_view_spend_logs_group_by_session_page_past_the_end_keeps_the_real_total(client, monkeypatch):
+    """An empty page past the last one says nothing about the total, so it is counted rather than inferred."""
+    sessions = tuple((f"sess-{index:02d}", f"2026-08-29 10:{59 - index:02d}:00") for index in range(100))
+    mock_prisma = _session_grouped_paginating_prisma(sessions)
+    monkeypatch.setattr("litellm.proxy.proxy_server.prisma_client", mock_prisma)
+    monkeypatch.setattr(
+        "litellm.proxy.spend_tracking.spend_management_endpoints._is_admin_view_safe",
+        lambda user_api_key_dict: True,
+    )
+    app.dependency_overrides[ps.user_api_key_auth] = lambda: UserAPIKeyAuth(
+        user_role=LitellmUserRoles.PROXY_ADMIN, user_id="admin_user"
+    )
+    try:
+        start_date, end_date = _default_date_range()
+        response = client.get(
+            "/spend/logs/ui",
+            params={
+                "start_date": start_date,
+                "end_date": end_date,
+                "group_by_session": "true",
+                "page": 4,
+                "page_size": 50,
+            },
+            headers={"Authorization": "Bearer sk-test"},
+        )
+        assert response.status_code == 200, response.text
+        data = response.json()
+        assert data["data"] == []
+        assert data["total"] == 100, "the empty page's offset is not a total"
+        assert data["total_pages"] == 2
+    finally:
+        app.dependency_overrides.pop(ps.user_api_key_auth, None)
+
+
 @pytest.mark.asyncio
 async def test_ui_view_spend_logs_group_by_session_page_past_count_cap_is_empty(client, monkeypatch):
     """The last page inside the capped total still lists sessions; the page after it is empty and costs no query."""