From 33e1b3b65196bcf61e9de22bb5051d6326b12dae Mon Sep 17 00:00:00 2001
From: Ishaan Jaff <ishaanjaffer0324@gmail.com>
Date: Thu, 24 Jul 2025 13:40:48 -0700
Subject: [PATCH] add async_pre_routing_hook

---
 litellm/integrations/custom_logger.py | 15 ++++++++++
 litellm/router.py                     | 41 +++++++++++++++++++++++++++
 2 files changed, 56 insertions(+)

diff --git a/litellm/integrations/custom_logger.py b/litellm/integrations/custom_logger.py
index a73dc6791e2..35e1193275b 100644
--- a/litellm/integrations/custom_logger.py
+++ b/litellm/integrations/custom_logger.py
@@ -125,6 +125,21 @@ class CustomLogger:  # https://docs.litellm.ai/docs/observability/custom_callbac
     Allows usage-based-routing-v2 to run pre-call rpm checks within the picked deployment's semaphore (concurrency-safe tpm/rpm checks).
     """
 
+    async def async_pre_routing_hook(
+        self,
+        model: str,
+        request_kwargs: Dict,
+        messages: Optional[List[Dict[str, str]]] = None,
+        input: Optional[Union[str, List]] = None,
+        specific_deployment: Optional[bool] = False,
+    ):
+        """
+        This hook is called before the routing decision is made.
+
+        Used for the litellm auto-router to modify the request before the routing decision is made.
+        """
+        pass
+
     async def async_filter_deployments(
         self,
         model: str,
diff --git a/litellm/router.py b/litellm/router.py
index 8eeb6e24170..89c2b166abd 100644
--- a/litellm/router.py
+++ b/litellm/router.py
@@ -6462,6 +6462,19 @@ class Router:
             )
         try:
             parent_otel_span = _get_parent_otel_span_from_kwargs(request_kwargs)
+            
+            #########################################################
+            # Execute Pre-Routing Hooks
+            #########################################################
+            await self.async_pre_routing_hook(
+                model=model,
+                request_kwargs=request_kwargs,
+                messages=messages,
+                input=input,
+                specific_deployment=specific_deployment,
+            )
+            
+            
             healthy_deployments = await self.async_get_healthy_deployments(
                 model=model,
                 request_kwargs=request_kwargs,
@@ -6572,6 +6585,34 @@ class Router:
                     )
             raise e
 
+    async def async_pre_routing_hook(
+        self,
+        model: str,
+        request_kwargs: Dict,
+        messages: Optional[List[Dict[str, str]]] = None,
+        input: Optional[Union[str, List]] = None,
+        specific_deployment: Optional[bool] = False,
+    ):
+        """
+        This hook is called before the routing decision is made.
+
+        Used for the litellm auto-router to modify the request before the routing decision is made.
+        """
+        custom_logger_callbacks: List[CustomLogger] = litellm.logging_callback_manager.get_custom_loggers_for_type(
+            callback_type=CustomLogger,
+        )
+        
+        for callback in custom_logger_callbacks:
+            await callback.async_pre_routing_hook(
+                model=model,
+                request_kwargs=request_kwargs,
+                messages=messages,
+                input=input,
+                specific_deployment=specific_deployment,
+            )
+
+
+
     def get_available_deployment(
         self,
         model: str,