refactor(examples): migrate all HTTP examples to streamable_http_app() (#2291)

examples/servers/simple-streamablehttp/README.md

@@ -6,9 +6,7 @@ A simple MCP server example demonstrating the StreamableHttp transport, which en
 
 - Uses the StreamableHTTP transport for server-client communication
 - Supports REST API operations (POST, GET, DELETE) for `/mcp` endpoint
-- Task management with anyio task groups
 - Ability to send multiple notifications over time to the client
-- Proper resource cleanup and lifespan management
 - Resumability support via InMemoryEventStore
 
 ## Usage

examples/servers/simple-streamablehttp/mcp_simple_streamablehttp/server.py

@@ -1,16 +1,11 @@
-import contextlib
 import logging
-from collections.abc import AsyncIterator
 
 import anyio
 import click
+import uvicorn
 from mcp import types
 from mcp.server import Server, ServerRequestContext
-from mcp.server.streamable_http_manager import StreamableHTTPSessionManager
-from starlette.applications import Starlette
 from starlette.middleware.cors import CORSMiddleware
-from starlette.routing import Mount
-from starlette.types import Receive, Scope, Send
 
 from .event_store import InMemoryEventStore
 
@@ -127,47 +122,21 @@ def main(
     # For production, use a persistent storage solution.
     event_store = InMemoryEventStore()
 
-    # Create the session manager with our app and event store
-    session_manager = StreamableHTTPSessionManager(
-        app=app,
-        event_store=event_store,  # Enable resumability
+    starlette_app = app.streamable_http_app(
+        event_store=event_store,
         json_response=json_response,
-    )
-
-    # ASGI handler for streamable HTTP connections
-    async def handle_streamable_http(scope: Scope, receive: Receive, send: Send) -> None:
-        await session_manager.handle_request(scope, receive, send)
-
-    @contextlib.asynccontextmanager
-    async def lifespan(app: Starlette) -> AsyncIterator[None]:
-        """Context manager for managing session manager lifecycle."""
-        async with session_manager.run():
-            logger.info("Application started with StreamableHTTP session manager!")
-            try:
-                yield
-            finally:
-                logger.info("Application shutting down...")
-
-    # Create an ASGI application using the transport
-    starlette_app = Starlette(
         debug=True,
-        routes=[
-            Mount("/mcp", app=handle_streamable_http),
-        ],
-        lifespan=lifespan,
     )
 
     # Wrap ASGI application with CORS middleware to expose Mcp-Session-Id header
     # for browser-based clients (ensures 500 errors get proper CORS headers)
     starlette_app = CORSMiddleware(
         starlette_app,
-        allow_origins=["*"],  # Allow all origins - adjust as needed for production
+        allow_origins=["*"],  # Note: streamable_http_app() enforces localhost-only Origin by default
         allow_methods=["GET", "POST", "DELETE"],  # MCP streamable HTTP methods
         expose_headers=["Mcp-Session-Id"],
     )
 
-    import uvicorn
-
     uvicorn.run(starlette_app, host="127.0.0.1", port=port)
 
     return 0