fix(fallback_budget): enforce team member budget on router fallback targets

litellm/proxy/auth/fallback_budget.py

@@ -130,6 +130,22 @@ async def is_token_within_budget_for_model(
     if is_model_cost_zero(model=model, llm_router=llm_router):
         return True
 
+    # Gating check: team member overall budget within their team. 
+    # Prevents zero-cost models with paid fallbacks from exceeding the member's team budget cap.
+    team_member_budget: Final = valid_token.team_member_budget
+    if (
+        team_member_budget is not None
+        and valid_token.user_id is not None
+        and valid_token.team_id is not None
+    ):
+        team_member_spend: Final = await _counter_spend(
+            counter_key=f"spend:team_member:{valid_token.user_id}:{valid_token.team_id}",
+            fallback_spend=valid_token.team_member_spend or 0.0,
+            max_budget=team_member_budget,
+        )
+        if team_member_spend >= team_member_budget:
+            return False
+
     key_budget: Final = valid_token.max_budget
     if key_budget is not None and valid_token.token is not None:
         key_spend: Final = await _counter_spend(

litellm/types/proxy/auth/user_api_key_auth.py

@@ -78,6 +78,7 @@ class LiteLLM_VerificationTokenView(LiteLLM_VerificationToken):
     team_member_spend: float | None = None
     team_member_tpm_limit: int | None = None
     team_member_rpm_limit: int | None = None
+    team_member_budget: float | None = None
 
     # End User Params
     end_user_id: str | None = None

tests/unit/proxy/auth/test_fallback_budget.py

@@ -115,6 +115,16 @@ async def test_paid_target_refused_when_over_user_budget():
     token = _token(user_spend=1900.0, user_max_budget=50.0)
     assert await is_token_within_budget_for_model(model="paid-model", valid_token=token, llm_router=_router()) is False
 
+@pytest.mark.asyncio
+async def test_paid_target_refused_when_over_team_member_budget():
+    token = _token(user_id="u1", team_id="t1", team_member_budget=50.0, team_member_spend=100.0)
+    assert await is_token_within_budget_for_model(model="paid-model", valid_token=token, llm_router=_router()) is False
+
+@pytest.mark.asyncio
+async def test_paid_target_allowed_when_under_team_member_budget():
+    token = _token(user_id="u1", team_id="t1", team_member_budget=50.0, team_member_spend=10.0)
+    assert await is_token_within_budget_for_model(model="paid-model", valid_token=token, llm_router=_router()) is True
+
 
 @pytest.mark.asyncio
 async def test_team_member_budget_refuses_an_exhausted_paid_target() -> None: