diff --git a/litellm/proxy/_experimental/mcp_server/auth/user_api_key_auth_mcp.py b/litellm/proxy/_experimental/mcp_server/auth/user_api_key_auth_mcp.py
index cf23a22505c..99ca192f3bd 100644
--- a/litellm/proxy/_experimental/mcp_server/auth/user_api_key_auth_mcp.py
+++ b/litellm/proxy/_experimental/mcp_server/auth/user_api_key_auth_mcp.py
@@ -179,7 +179,9 @@ class MCPRequestHandler:
         elif (
             not litellm_api_key
             and MCPRequestHandler._target_servers_delegate_auth_to_upstream(  # noqa: E501
-                path=request.url.path, mcp_servers=mcp_servers
+                path=request.url.path,
+                mcp_servers=mcp_servers,
+                client_ip=IPAddressUtils.get_mcp_client_ip(request),
             )
         ):
             # Operator opted this oauth2 server into upstream-delegated auth
@@ -379,7 +381,7 @@ class MCPRequestHandler:
 
     @staticmethod
     def _target_servers_delegate_auth_to_upstream(
-        path: str, mcp_servers: Optional[List[str]]
+        path: str, mcp_servers: Optional[List[str]], client_ip: Optional[str]
     ) -> bool:
         """
         True only when EVERY MCP server the request targets is configured for
@@ -409,7 +411,9 @@ class MCPRequestHandler:
             return False
 
         for name in target_names:
-            server = global_mcp_server_manager.get_mcp_server_by_name(name)
+            server = global_mcp_server_manager.get_mcp_server_by_name(
+                name, client_ip=client_ip
+            )
             if server is None or server.auth_type != MCPAuth.oauth2:
                 return False
             # `is True` is intentional: opt-in must be an explicit boolean
diff --git a/tests/test_litellm/proxy/_experimental/mcp_server/auth/test_user_api_key_auth_mcp.py b/tests/test_litellm/proxy/_experimental/mcp_server/auth/test_user_api_key_auth_mcp.py
index f719b40fe74..beae2bb61d2 100644
--- a/tests/test_litellm/proxy/_experimental/mcp_server/auth/test_user_api_key_auth_mcp.py
+++ b/tests/test_litellm/proxy/_experimental/mcp_server/auth/test_user_api_key_auth_mcp.py
@@ -1,7 +1,7 @@
 import json
 import os
 import sys
-from unittest.mock import AsyncMock, MagicMock, patch
+from unittest.mock import AsyncMock, MagicMock, call as mock_call, patch
 
 import pytest
 from fastapi.testclient import TestClient
@@ -918,7 +918,9 @@ class TestMCPPassthroughColdStartAdmission:
                 await MCPRequestHandler.process_mcp_request(scope)
 
             assert exc_info.value.status_code == 401
-            mock_mgr.get_mcp_server_by_name.assert_not_called()
+            mock_mgr.get_mcp_server_by_name.assert_called_once_with(
+                "passthrough_server", client_ip=""
+            )
 
     async def test_cold_start_rejects_server_specific_authorization_header(self):
         from fastapi import HTTPException
@@ -1016,7 +1018,7 @@ class TestMCPPassthroughColdStartAdmission:
                 await MCPRequestHandler.process_mcp_request(scope)
 
             assert exc_info.value.status_code == 401
-            mock_mgr.get_mcp_server_by_name.assert_called_once_with(
+            assert mock_mgr.get_mcp_server_by_name.call_args_list[-1] == mock_call(
                 "passthrough_server", client_ip="203.0.113.10"
             )
 
@@ -1111,7 +1113,7 @@ class TestMCPPassthroughColdStartAdmission:
             (auth_result, *_rest) = await MCPRequestHandler.process_mcp_request(scope)
 
             assert isinstance(auth_result, UserAPIKeyAuth)
-            mock_mgr.get_mcp_server_by_name.assert_called_once_with(
+            assert mock_mgr.get_mcp_server_by_name.call_args_list[-1] == mock_call(
                 "passthrough_server", client_ip=""
             )
 
@@ -1148,7 +1150,7 @@ class TestMCPPassthroughColdStartAdmission:
             (auth_result, *_rest) = await MCPRequestHandler.process_mcp_request(scope)
 
             assert isinstance(auth_result, UserAPIKeyAuth)
-            mock_mgr.get_mcp_server_by_name.assert_called_once_with(
+            assert mock_mgr.get_mcp_server_by_name.call_args_list[-1] == mock_call(
                 "passthrough_server", client_ip=""
             )
 
@@ -1996,7 +1998,7 @@ class TestMCPDelegateAuthToUpstream:
             delegate_auth_to_upstream=True,
         )
 
-        def lookup_by_name(name):
+        def lookup_by_name(name, **_kwargs):
             # Only the *exact* delegated name resolves. Anything else (e.g.
             # ``delegated_server/extra``) returns None so the bypass fails.
             if name == "delegated_server":
@@ -2059,7 +2061,7 @@ class TestMCPDelegateAuthToUpstream:
             auth_type=MCPAuth.api_key,
         )
 
-        def lookup_by_name(name):
+        def lookup_by_name(name, **_kwargs):
             return {
                 "delegated_server": delegate_server,
                 "non_delegate_server": non_delegate,