fix(mcp_server_manager.py): support static headers

litellm/proxy/_experimental/mcp_server/mcp_server_manager.py

@@ -218,6 +218,7 @@ class MCPServerManager:
                 disallowed_tools=server_config.get("disallowed_tools", None),
                 allowed_params=server_config.get("allowed_params", None),
                 access_groups=server_config.get("access_groups", None),
+                static_headers=server_config.get("static_headers", None),
             )
             self.config_mcp_servers[server_id] = new_server
 
@@ -632,6 +633,11 @@ class MCPServerManager:
         client = None
 
         try:
+            if server.static_headers:
+                if extra_headers is None:
+                    extra_headers = {}
+                extra_headers.update(server.static_headers)
+
             client = self._create_mcp_client(
                 server=server,
                 mcp_auth_header=mcp_auth_header,
@@ -1098,12 +1104,16 @@ class MCPServerManager:
         server_auth_header: Optional[Union[Dict[str, str], str]] = None
         if mcp_server_auth_headers:
             # Normalize keys for case-insensitive lookup
-            normalized_headers = {k.lower(): v for k, v in mcp_server_auth_headers.items()}
-            
+            normalized_headers = {
+                k.lower(): v for k, v in mcp_server_auth_headers.items()
+            }
+
             if mcp_server.alias:
                 server_auth_header = normalized_headers.get(mcp_server.alias.lower())
             if server_auth_header is None and mcp_server.server_name:
-                server_auth_header = normalized_headers.get(mcp_server.server_name.lower())
+                server_auth_header = normalized_headers.get(
+                    mcp_server.server_name.lower()
+                )
 
         # Fall back to deprecated mcp_auth_header if no server-specific header found
         if server_auth_header is None:
@@ -1121,6 +1131,11 @@ class MCPServerManager:
                 if header in raw_headers:
                     extra_headers[header] = raw_headers[header]
 
+        if mcp_server.static_headers:
+            if extra_headers is None:
+                extra_headers = {}
+            extra_headers.update(mcp_server.static_headers)
+
         client = self._create_mcp_client(
             server=mcp_server,
             mcp_auth_header=server_auth_header,

litellm/proxy/_new_secret_config.yaml

@@ -19,3 +19,11 @@ vector_store_registry:
         api_base: https://krris-mh44uf7y-eastus2.cognitiveservices.azure.com/
         api_key: os.environ/AZURE_API_KEY
         api_version: "2025-09-01"
+mcp_servers:
+  local_fake_mcp:
+    url: "http://127.0.0.1:8001/mcp"
+    transport: "http"
+    description: "My custom MCP server"
+    auth_type: "api_key"
+    auth_value: "abc123"
+    static_headers: {"X-API-Key": "abc123"}

litellm/types/mcp_server/mcp_server_manager.py

@@ -22,7 +22,7 @@ class MCPServer(BaseModel):
     authentication_token: Optional[str] = None
     mcp_info: Optional[MCPInfo] = None
     extra_headers: Optional[List[str]] = (
-        None  # allow admin to specify which headers to forward to the MCP server
+        None  # allow admin to specify which headers to forward from client to the MCP server
     )
     allowed_tools: Optional[List[str]] = None
     disallowed_tools: Optional[List[str]] = None
@@ -40,4 +40,7 @@ class MCPServer(BaseModel):
     args: Optional[List[str]] = None
     env: Optional[Dict[str, str]] = None
     access_groups: Optional[List[str]] = None
+    static_headers: Optional[Dict[str, str]] = (
+        None  # static headers to forward to the MCP server
+    )
     model_config = ConfigDict(arbitrary_types_allowed=True)