feat: add UI banner warning for detailed debug mode

Add a prominent warning banner to the UI dashboard when detailed debug
mode (LITELLM_LOG=DEBUG) is enabled. This alerts users to significant
performance degradation caused by extensive diagnostic logging.

Backend changes:
- Enhanced /health/readiness endpoint to include log_level and
  is_detailed_debug fields
- Added detection using verbose_logger.getEffectiveLevel()
- Backward compatible - old clients ignore new fields

Frontend changes:
- Updated useHealthReadiness TypeScript interface
- Created DebugWarningBanner component using Ant Design Alert
- Integrated banner into dashboard layout below navbar
- Banner only shows when DEBUG level is active
- Non-dismissible to ensure users are aware of performance impact

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

litellm/proxy/health_endpoints/_health_endpoints.py

@@ -1,5 +1,6 @@
 import asyncio
 import copy
+import logging
 import os
 import time
 import traceback
@@ -10,8 +11,9 @@ import fastapi
 from fastapi import APIRouter, Depends, HTTPException, Request, Response, status
 
 import litellm
-from litellm._logging import verbose_proxy_logger
+from litellm._logging import verbose_logger, verbose_proxy_logger
 from litellm.constants import HEALTH_CHECK_TIMEOUT_SECONDS
+from litellm.litellm_core_utils.custom_logger_registry import CustomLoggerRegistry
 from litellm.llms.custom_httpx.http_handler import AsyncHTTPHandler
 from litellm.proxy._types import (
     AlertType,
@@ -32,7 +34,6 @@ from litellm.proxy.health_check import (
     run_with_timeout,
 )
 from litellm.secret_managers.main import get_secret
-from litellm.litellm_core_utils.custom_logger_registry import CustomLoggerRegistry
 
 #### Health ENDPOINTS ####
 
@@ -1007,10 +1008,7 @@ async def shared_health_check_status_endpoint(
 
 
 def _read_license_data() -> Optional[Dict[str, Any]]:
-    from litellm.proxy.proxy_server import (
-        _license_check,
-        premium_user_data,
-    )
+    from litellm.proxy.proxy_server import _license_check, premium_user_data
 
     license_data: Optional[EnterpriseLicenseData] = (
         premium_user_data or _license_check.airgapped_license_data
@@ -1054,10 +1052,7 @@ async def health_license_endpoint(
     user_api_key_dict: UserAPIKeyAuth = Depends(user_api_key_auth),
 ):
     """Return metadata about the configured LiteLLM license without exposing the key."""
-    from litellm.proxy.proxy_server import (
-        _license_check,
-        premium_user,
-    )
+    from litellm.proxy.proxy_server import _license_check, premium_user
 
     license_data = _read_license_data()
     has_license = bool(getattr(_license_check, "license_str", None))
@@ -1251,6 +1246,10 @@ async def health_readiness():
                     index_info = "index does not exist - error: " + str(e)
                 cache_type = {"type": cache_type, "index_info": index_info}
 
+        # check log level
+        log_level_name = logging.getLevelName(verbose_logger.getEffectiveLevel())
+        is_detailed_debug = verbose_logger.isEnabledFor(logging.DEBUG)
+
         # check DB
         if prisma_client is not None:  # if db passed in, check if it's connected
             db_health_status = await _db_health_readiness_check()
@@ -1261,6 +1260,8 @@ async def health_readiness():
                 "litellm_version": version,
                 "success_callbacks": success_callback_names,
                 "use_aiohttp_transport": AsyncHTTPHandler._should_use_aiohttp_transport(),
+                "log_level": log_level_name,
+                "is_detailed_debug": is_detailed_debug,
                 **db_health_status,
             }
         else:
@@ -1271,6 +1272,8 @@ async def health_readiness():
                 "litellm_version": version,
                 "success_callbacks": success_callback_names,
                 "use_aiohttp_transport": AsyncHTTPHandler._should_use_aiohttp_transport(),
+                "log_level": log_level_name,
+                "is_detailed_debug": is_detailed_debug,
             }
     except Exception as e:
         raise HTTPException(status_code=503, detail=f"Service Unhealthy ({str(e)})")

ui/litellm-dashboard/src/app/(dashboard)/hooks/healthReadiness/useHealthReadiness.ts

@@ -6,6 +6,8 @@ const healthReadinessKeys = createQueryKeys("healthReadiness");
 
 interface HealthReadinessResponse {
   litellm_version?: string;
+  log_level?: string;
+  is_detailed_debug?: boolean;
   [key: string]: any;
 }
 

ui/litellm-dashboard/src/app/(dashboard)/layout.tsx

@@ -6,6 +6,7 @@ import { ThemeProvider } from "@/contexts/ThemeContext";
 import Sidebar2 from "@/app/(dashboard)/components/Sidebar2";
 import useAuthorized from "@/app/(dashboard)/hooks/useAuthorized";
 import { useRouter, useSearchParams } from "next/navigation";
+import { DebugWarningBanner } from "@/components/DebugWarningBanner";
 
 /** ---- BASE URL HELPERS ---- */
 function normalizeBasePrefix(raw: string | undefined | null): string {
@@ -61,6 +62,7 @@ function LayoutContent({ children }: { children: React.ReactNode }) {
           isDarkMode={false}
           toggleDarkMode={() => { }}
         />
+        <DebugWarningBanner />
         <div className="flex flex-1 overflow-auto">
           <div className="mt-2">
             <Sidebar2 defaultSelectedKey={page} accessToken={accessToken} userRole={userRole} />

ui/litellm-dashboard/src/components/DebugWarningBanner.tsx

@@ -0,0 +1,32 @@
+"use client";
+
+import React from "react";
+import { Alert } from "antd";
+import { useHealthReadiness } from "@/app/(dashboard)/hooks/healthReadiness/useHealthReadiness";
+
+export const DebugWarningBanner: React.FC = () => {
+  const { data: healthData } = useHealthReadiness();
+
+  // Only show banner if detailed debug mode is explicitly enabled
+  if (!healthData?.is_detailed_debug) {
+    return null;
+  }
+
+  return (
+    <Alert
+      message="Performance Warning: Detailed Debug Mode Active"
+      description={
+        <>
+          Detailed debug logging (<code>LITELLM_LOG=DEBUG</code>) is currently
+          enabled. This mode logs extensive diagnostic information and will
+          significantly degrade performance. It should only be used for
+          troubleshooting and disabled in production environments.
+        </>
+      }
+      type="warning"
+      showIcon
+      banner
+      style={{ marginBottom: 0, borderRadius: 0 }}
+    />
+  );
+};