Add streamable_http_client which accepts httpx.AsyncClient instead of httpx_client_factory (#1177)

Co-authored-by: Felix Weinberger <fweinberger@anthropic.com>

src/mcp/client/session_group.py

@@ -17,6 +17,7 @@ from types import TracebackType
 from typing import Any, TypeAlias, overload
 
 import anyio
+import httpx
 from pydantic import BaseModel
 from typing_extensions import Self, deprecated
 
@@ -25,7 +26,8 @@ from mcp import types
 from mcp.client.session import ElicitationFnT, ListRootsFnT, LoggingFnT, MessageHandlerFnT, SamplingFnT
 from mcp.client.sse import sse_client
 from mcp.client.stdio import StdioServerParameters
-from mcp.client.streamable_http import streamablehttp_client
+from mcp.client.streamable_http import streamable_http_client
+from mcp.shared._httpx_utils import create_mcp_http_client
 from mcp.shared.exceptions import McpError
 from mcp.shared.session import ProgressFnT
 
@@ -47,7 +49,7 @@ class SseServerParameters(BaseModel):
 
 
 class StreamableHttpParameters(BaseModel):
-    """Parameters for intializing a streamablehttp_client."""
+    """Parameters for intializing a streamable_http_client."""
 
     # The endpoint URL.
     url: str
@@ -309,11 +311,18 @@ class ClientSessionGroup:
                 )
                 read, write = await session_stack.enter_async_context(client)
             else:
-                client = streamablehttp_client(
-                    url=server_params.url,
+                httpx_client = create_mcp_http_client(
                     headers=server_params.headers,
-                    timeout=server_params.timeout,
-                    sse_read_timeout=server_params.sse_read_timeout,
+                    timeout=httpx.Timeout(
+                        server_params.timeout.total_seconds(),
+                        read=server_params.sse_read_timeout.total_seconds(),
+                    ),
+                )
+                await session_stack.enter_async_context(httpx_client)
+
+                client = streamable_http_client(
+                    url=server_params.url,
+                    http_client=httpx_client,
                     terminate_on_close=server_params.terminate_on_close,
                 )
                 read, write, _ = await session_stack.enter_async_context(client)