Add exports and deprecation warning

- Export Client from mcp and mcp.client modules
- Add deprecation warning to create_connected_server_and_client_session
- Document migration path in docstring

Github-Issue:#1728

Author: felixweinberger

src/mcp/__init__.py

@@ -1,3 +1,4 @@
+from .client.client import Client
 from .client.session import ClientSession
 from .client.session_group import ClientSessionGroup
 from .client.stdio import StdioServerParameters, stdio_client
@@ -66,6 +67,7 @@
 
 __all__ = [
     "CallToolRequest",
+    "Client",
     "ClientCapabilities",
     "ClientNotification",
     "ClientRequest",

src/mcp/client/__init__.py

@@ -0,0 +1,13 @@
+"""MCP Client module."""
+
+from mcp.client.client import Client
+from mcp.client.session import ClientSession
+from mcp.client.session_group import ClientSessionGroup
+from mcp.client.transports.memory import create_in_memory_transport
+
+__all__ = [
+    "Client",
+    "ClientSession",
+    "ClientSessionGroup",
+    "create_in_memory_transport",
+]

src/mcp/shared/memory.py

@@ -4,6 +4,7 @@
 
 from __future__ import annotations
 
+import warnings
 from collections.abc import AsyncGenerator
 from contextlib import asynccontextmanager
 from typing import Any
@@ -57,10 +58,30 @@ async def create_connected_server_and_client_session(
     raise_exceptions: bool = False,
     elicitation_callback: ElicitationFnT | None = None,
 ) -> AsyncGenerator[ClientSession, None]:
-    """Creates a ClientSession that is connected to a running MCP server."""
+    """Creates a ClientSession that is connected to a running MCP server.
+
+    .. deprecated::
+        Use :class:`mcp.client.Client` with :meth:`Client.from_server` instead.
+        This function will be removed in a future version.
+
+        Example migration::
+
+            # Before
+            async with create_connected_server_and_client_session(server) as session:
+                result = await session.call_tool("my_tool", {...})
+
+            # After
+            from mcp import Client
+            async with Client.from_server(server) as client:
+                result = await client.call_tool("my_tool", {...})
+    """
+    warnings.warn(
+        "create_connected_server_and_client_session is deprecated. "
+        "Use Client.from_server(server) instead.",
+        DeprecationWarning,
+        stacklevel=2,
+    )
 
-    # TODO(Marcelo): we should have a proper `Client` that can use this "in-memory transport",
-    # and we should expose a method in the `FastMCP` so we don't access a private attribute.
     if isinstance(server, FastMCP):  # pragma: no cover
         server = server._mcp_server  # type: ignore[reportPrivateUsage]