From 168bc38d814a87004be7944ee10a353756325650 Mon Sep 17 00:00:00 2001
From: Tin Chi Lo <tin@berri.ai>
Date: Sat, 11 Jul 2026 10:44:23 -0700
Subject: [PATCH] fix(mcp): strip scheme default port from get_request_base_url
 netloc

---
 .../_experimental/mcp_server/oauth_utils.py   |  2 +-
 .../mcp_server/test_discoverable_endpoints.py | 35 +++++++++++++++++++
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/litellm/proxy/_experimental/mcp_server/oauth_utils.py b/litellm/proxy/_experimental/mcp_server/oauth_utils.py
index 4d5813dbc5bf..6edb22dd858e 100644
--- a/litellm/proxy/_experimental/mcp_server/oauth_utils.py
+++ b/litellm/proxy/_experimental/mcp_server/oauth_utils.py
@@ -129,7 +129,7 @@ def get_request_base_url(request: Request) -> str:
         if x_forwarded_port and ":" not in netloc:
             netloc = f"{netloc}:{x_forwarded_port}"
 
-    return urlunparse((scheme, netloc, parsed.path, "", "", ""))
+    return urlunparse((scheme, _strip_default_port(scheme, netloc), parsed.path, "", "", ""))
 
 
 def validate_loopback_redirect_uri(redirect_uri: str) -> None:
diff --git a/tests/test_litellm/proxy/_experimental/mcp_server/test_discoverable_endpoints.py b/tests/test_litellm/proxy/_experimental/mcp_server/test_discoverable_endpoints.py
index 11a6fea0ceaf..258156ede516 100644
--- a/tests/test_litellm/proxy/_experimental/mcp_server/test_discoverable_endpoints.py
+++ b/tests/test_litellm/proxy/_experimental/mcp_server/test_discoverable_endpoints.py
@@ -1848,6 +1848,41 @@ async def test_token_endpoint_respects_x_forwarded_host():
             None,
             "https://external.com",
         ),
+        (
+            "http://localhost:4000/",
+            "https",
+            "proxy.example.com",
+            "443",
+            "https://proxy.example.com",
+        ),
+        (
+            "http://localhost:4000/",
+            "http",
+            "proxy.example.com",
+            "80",
+            "http://proxy.example.com",
+        ),
+        (
+            "http://internal.local/",
+            "https",
+            None,
+            "443",
+            "https://internal.local",
+        ),
+        (
+            "http://localhost:4000/",
+            "https",
+            "proxy.example.com",
+            "8443",
+            "https://proxy.example.com:8443",
+        ),
+        (
+            "http://localhost:4000/",
+            "https",
+            "proxy.example.com:443",
+            None,
+            "https://proxy.example.com",
+        ),
     ],
 )
 def test_get_request_base_url_comprehensive(