add comments to server example where we use related_request_id

Author: ihrpr

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

@@ -82,6 +82,11 @@ async def call_tool(
                 level="info",
                 data=f"Notification {i+1}/{count} from caller: {caller}",
                 logger="notification_stream",
+                # Associates this notification with the original request
+                # Ensures notifications are sent to the correct response stream
+                # Without this, notifications will either go to:
+                # - a standalone SSE stream (if GET request is supported)
+                # - nowhere (if GET request isn't supported)
                 related_request_id=ctx.request_id,
             )
             if i < count - 1:  # Don't wait after the last notification

src/mcp/server/fastmcp/server.py

@@ -466,6 +466,7 @@ async def run_stdio_async(self) -> None:
     async def run_sse_async(self) -> None:
         """Run the server using SSE transport."""
         import uvicorn
+
         starlette_app = self.sse_app()
 
         config = uvicorn.Config(
@@ -673,7 +674,10 @@ async def log(
             **extra: Additional structured data to include
         """
         await self.request_context.session.send_log_message(
-            level=level, data=message, logger=logger_name
+            level=level,
+            data=message,
+            logger=logger_name,
+            related_request_id=self.request_id,
         )
 
     @property