[v2] Dispatcher/ServerRunner receive-path swap — replaces BaseSession (#2710)

src/mcp/server/__main__.py

@@ -1,14 +1,11 @@
-import importlib.metadata
 import logging
 import sys
 import warnings
 
 import anyio
 
-from mcp.server.models import InitializationOptions
-from mcp.server.session import ServerSession
+from mcp.server.lowlevel.server import Server
 from mcp.server.stdio import stdio_server
-from mcp.types import ServerCapabilities
 
 if not sys.warnoptions:
     warnings.simplefilter("ignore")
@@ -17,32 +14,10 @@ logging.basicConfig(level=logging.INFO)
 logger = logging.getLogger("server")
 
 
-async def receive_loop(session: ServerSession):
-    logger.info("Starting receive loop")
-    async for message in session.incoming_messages:
-        if isinstance(message, Exception):
-            logger.error("Error: %s", message)
-            continue
-
-        logger.info("Received message from client: %s", message)
-
-
-async def main():
-    version = importlib.metadata.version("mcp")
+async def main() -> None:
+    server: Server[dict[str, object]] = Server("mcp")
     async with stdio_server() as (read_stream, write_stream):
-        async with (
-            ServerSession(
-                read_stream,
-                write_stream,
-                InitializationOptions(
-                    server_name="mcp",
-                    server_version=version,
-                    capabilities=ServerCapabilities(),
-                ),
-            ) as session,
-            write_stream,
-        ):
-            await receive_loop(session)
+        await server.run(read_stream, write_stream, server.create_initialization_options())
 
 
 if __name__ == "__main__":