fix(proxy): warn at startup when max_budget is set but no database is connected (#36041)

* warn at startup when a proxy-wide budget is set but no DB is connected

litellm.max_budget is only enforced via DB-loaded global spend, so a DB-less proxy silently ignores it. Log a one-time startup warning.

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

* refactor(proxy): inject max_budget into DB-less budget warning

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

* test(proxy): cover DB-less budget warning startup call

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

* test(proxy): pin DB-less budget warning call site

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

* test(proxy): stabilize budget warning call-site pin

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

---------

Co-authored-by: tin <tin@berri.ai>
Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

litellm/proxy/proxy_server.py

@@ -1111,6 +1111,10 @@ async def proxy_startup_event(app: FastAPI):
                 prisma_client=prisma_client,
             )
         )
+    ProxyStartupEvent._warn_budget_without_db(
+        max_budget=litellm.max_budget,
+        prisma_client=prisma_client,
+    )
 
     ### START BATCH WRITING DB + CHECKING NEW MODELS###
     if prisma_client is not None:
@@ -7825,6 +7829,19 @@ def giveup(e):
 
 
 class ProxyStartupEvent:
+    @staticmethod
+    def _warn_budget_without_db(max_budget: float | None, prisma_client: PrismaClient | None) -> None:
+        if prisma_client is not None or not max_budget or max_budget <= 0:
+            return
+
+        verbose_proxy_logger.warning(
+            "A proxy-wide budget (litellm.max_budget=%s) is configured but no database is connected, "
+            "so the budget will NOT be enforced and requests will never be blocked. Set DATABASE_URL or "
+            "general_settings.database_url and restart. Redis and fail_closed_budget_enforcement do not "
+            "cover the proxy-wide budget because there is no global spend counter; Redis alone is not a substitute.",
+            max_budget,
+        )
+
     @classmethod
     def _initialize_startup_logging(
         cls,

tests/test_litellm/proxy/proxy_server/test_lifecycle.py

@@ -20,6 +20,7 @@ from __future__ import annotations
 import asyncio
 import inspect
 import json
+import logging
 import os
 from typing import List, Optional, Union
 from unittest.mock import AsyncMock, MagicMock, patch
@@ -31,6 +32,7 @@ from typing_extensions import TypedDict
 
 import litellm.proxy.proxy_server as ps
 from litellm.proxy.proxy_server import (
+    ProxyStartupEvent,
     _initialize_shared_aiohttp_session,
     _resolve_pydantic_type,
     _resolve_typed_dict_type,
@@ -728,3 +730,50 @@ def test_otel_global_provider_published_after_callback_init():
         "preset logger will not exist yet and a second generic logger will own "
         "the global provider, orphaning gen-ai spans"
     )
+
+
+def test_startup_warns_for_global_budget_without_database(caplog):
+    with caplog.at_level(logging.WARNING, logger="LiteLLM Proxy"):
+        ProxyStartupEvent._warn_budget_without_db(max_budget=100.0, prisma_client=None)
+
+    assert "litellm.max_budget=100.0" in caplog.text
+    assert "will NOT be enforced" in caplog.text
+    assert "requests will never be blocked" in caplog.text
+
+
+def test_startup_does_not_warn_for_global_budget_with_database(caplog):
+    with caplog.at_level(logging.WARNING, logger="LiteLLM Proxy"):
+        ProxyStartupEvent._warn_budget_without_db(max_budget=100.0, prisma_client=MagicMock())
+
+    assert "litellm.max_budget" not in caplog.text
+
+
+@pytest.mark.parametrize("max_budget", [0, None])
+def test_startup_does_not_warn_without_global_budget(caplog, max_budget):
+    with caplog.at_level(logging.WARNING, logger="LiteLLM Proxy"):
+        ProxyStartupEvent._warn_budget_without_db(max_budget=max_budget, prisma_client=None)
+
+    assert "litellm.max_budget" not in caplog.text
+
+
+def test_proxy_startup_event_warns_for_global_budget_without_database():
+    """Pin the lifespan call that prevents silent DB-less budgets.
+
+    The call must follow Prisma setup so DB-backed deployments do not false-positive.
+    Direct ``_warn_budget_without_db`` tests cover the warning behavior itself.
+    """
+    wrapped = getattr(proxy_startup_event, "__wrapped__", proxy_startup_event)
+    source = inspect.getsource(wrapped)
+    budget_check_pos = source.find("if prisma_client is not None and litellm.max_budget > 0:")
+    warn_pos = source.find("_warn_budget_without_db(")
+    next_startup_section_pos = source.find(
+        "await ProxyStartupEvent.initialize_scheduled_background_jobs(",
+        budget_check_pos,
+    )
+
+    assert budget_check_pos != -1, "global budget startup block not found"
+    assert warn_pos != -1, "DB-less budget warning call not found"
+    assert next_startup_section_pos != -1, "startup section after budget block not found"
+    assert budget_check_pos < warn_pos < next_startup_section_pos, (
+        "DB-less budget warning must run after Prisma setup and the DB-backed budget block"
+    )