How to receive notifications on mcp client side? #889

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1. kylestratis commented on Jun 9, 2025

   

   kylestratis

   on Jun 9, 2025

   More actions

   👍
   It doesn't seem like notification handling is yet built into the Python SDK

   😕React with 😕4Reacted by Ricardo, LatentLinker, HailouWang and kawashi-h
2. felixweinberger

   added

   improves spec complianceWhen a change improves ability of SDK users to comply with spec definitionWhen a change improves ability of SDK users to comply with spec definition

   enhancementRequest for a new feature that's not currently supportedRequest for a new feature that's not currently supported

   ready for workEnough information for someone to start working onEnough information for someone to start working on

   P0Broken core functionality, security issues, critical missing featureBroken core functionality, security issues, critical missing feature

   improves sdk consistencyImproves consistency with other SDKs such as TyepscriptImproves consistency with other SDKs such as Tyepscript

   on Oct 7, 2025
3. felixweinberger

   added this to the FastMCP issues milestone on Oct 7, 2025
4. maxisbey commented on Jan 5, 2026

   

   maxisbey

   on Jan 5, 2026

   Last edited by maxisbey

   Contributor

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   The SDK partially supports receiving notifications on the client side today:

   Notification Type	Current Support
   LoggingMessageNotification	✅ logging_callback
   ProgressNotification	✅ progress_callback on call_tool()
   CancelledNotification	✅ Automatic
   ResourceListChangedNotification	❌ message_handler only
   ResourceUpdatedNotification	❌ message_handler only
   ToolListChangedNotification	❌ message_handler only
   PromptListChangedNotification	❌ message_handler only
   ElicitCompleteNotification	❌ message_handler only
   TaskStatusNotification	❌ message_handler only

   For logging notifications (Context.info(), etc.), pass a logging_callback to ClientSession:

   async def handle_log(params: types.LoggingMessageNotificationParams) -> None:
       print(f"[{params.level}] {params.data}")
   
   async with ClientSession(read, write, logging_callback=handle_log) as session:
       ...

   For progress notifications, pass a progress_callback when calling a tool:

   await session.call_tool("my_tool", {}, progress_callback=on_progress)

   For other notifications (resource/tool/prompt list changes, etc.), use the generic message_handler parameter:

   from mcp.shared.session import RequestResponder
   import mcp.types as types
   
   async def handle_notifications(
       message: RequestResponder[types.ServerRequest, types.ClientResult] | types.ServerNotification | Exception,
   ) -> None:
       if isinstance(message, types.ServerNotification):
           match message.root:
               case types.ResourceListChangedNotification():
                   print("Resources changed, refreshing list...")
               case types.ToolListChangedNotification():
                   print("Tools changed, refreshing list...")
               case types.PromptListChangedNotification():
                   print("Prompts changed, refreshing list...")
   
   async with ClientSession(read, write, message_handler=handle_notifications) as session:
       ...

   We do want to add proper dedicated callbacks for all notification types. PR #1611 addresses this but hasn't been reviewed yet.

   As this issue is quite old, I'm closing it for now. Feel free to re-open if you have further questions.

   _{AI Disclaimer}
5. maxisbey

   closed this as completedon Jan 5, 2026
6. felixweinberger

   added

   P1Significant bug affecting many users, highly requested featureSignificant bug affecting many users, highly requested feature

   and removed

   P0Broken core functionality, security issues, critical missing featureBroken core functionality, security issues, critical missing feature

   on Feb 23, 2026