add type field to client session config BaseModels

Author: bfineran

src/mcp/client/session_group.py

@@ -13,7 +13,7 @@
 from collections.abc import Callable
 from datetime import timedelta
 from types import TracebackType
-from typing import Any, TypeAlias
+from typing import Any, Literal, TypeAlias
 
 import anyio
 from pydantic import BaseModel
@@ -29,6 +29,9 @@
 
 class SseServerParameters(BaseModel):
     """Parameters for intializing a sse_client."""
+    
+    # The type of server connection.
+    type: Literal["sse"] = "sse"
 
     # The endpoint URL.
     url: str
@@ -45,6 +48,9 @@ class SseServerParameters(BaseModel):
 
 class StreamableHttpParameters(BaseModel):
     """Parameters for intializing a streamablehttp_client."""
+    
+    # The type of server connection.
+    type: Literal["streamable_http"] = "streamable_http"
 
     # The endpoint URL.
     url: str

src/mcp/client/stdio/__init__.py

@@ -69,6 +69,9 @@ def get_default_environment() -> dict[str, str]:
 
 
 class StdioServerParameters(BaseModel):
+    type: Literal["stdio"] = "stdio"
+    """The type of server connection."""
+
     command: str
     """The executable to run to start the server."""