Client notification support

README.md

@@ -2153,6 +2153,56 @@ if __name__ == "__main__":
 _Full example: [examples/snippets/clients/streamable_basic.py](https://github.com/modelcontextprotocol/python-sdk/blob/main/examples/snippets/clients/streamable_basic.py)_
 <!-- /snippet-source -->
 
+### Handling Server Notifications
+
+Servers may send notifications, which derive from the `ServerNotification` class. To handle these, follow the following steps:
+
+1. For each notification type you want to support, write a callback function that follows implements the matching protocol, such as `ToolListChangedFnT` for the tool list changed notification.
+2. Pass that function to the appropriate parameter when instantiating your client, e.g. `tool_list_changed_callback` for the tool list changed notification. This will be called every time your client receives the matching notification.
+
+<!-- snippet-source examples/snippets/clients/server_notification_client.py -->
+```python
+# Snippets demonstrating handling known and custom server notifications
+
+import asyncio
+
+from mcp import ClientSession, StdioServerParameters
+from mcp.client.stdio import stdio_client
+
+# Create dummy server parameters for stdio connection
+server_params = StdioServerParameters(
+    command="uv",
+    args=["run"],
+    env={},
+)
+
+
+# Create a custom handler for the resource list changed notification
+async def custom_resource_list_changed_handler() -> None:
+    """Custom handler for resource list changed notifications."""
+    print("RESOURCE LIST CHANGED")
+
+
+async def run():
+    async with stdio_client(server_params) as (read, write):
+        async with ClientSession(
+            read,
+            write,
+            resource_list_changed_callback=custom_resource_list_changed_handler,
+        ) as session:
+            # Initialize the connection
+            await session.initialize()
+
+            # Do client stuff here
+
+
+if __name__ == "__main__":
+    asyncio.run(run())
+```
+
+_Full example: [examples/snippets/clients/server_notification_client.py](https://github.com/modelcontextprotocol/python-sdk/blob/main/examples/snippets/clients/server_notification_client.py)_
+<!-- /snippet-source -->
+
 ### Client Display Utilities
 
 When building MCP clients, the SDK provides utilities to help display human-readable names for tools, resources, and prompts:

examples/snippets/clients/server_notification_client.py

@@ -0,0 +1,36 @@
+# Snippets demonstrating handling known and custom server notifications
+
+import asyncio
+
+from mcp import ClientSession, StdioServerParameters
+from mcp.client.stdio import stdio_client
+
+# Create dummy server parameters for stdio connection
+server_params = StdioServerParameters(
+    command="uv",
+    args=["run"],
+    env={},
+)
+
+
+# Create a custom handler for the resource list changed notification
+async def custom_resource_list_changed_handler() -> None:
+    """Custom handler for resource list changed notifications."""
+    print("RESOURCE LIST CHANGED")
+
+
+async def run():
+    async with stdio_client(server_params) as (read, write):
+        async with ClientSession(
+            read,
+            write,
+            resource_list_changed_callback=custom_resource_list_changed_handler,
+        ) as session:
+            # Initialize the connection
+            await session.initialize()
+
+            # Do client stuff here
+
+
+if __name__ == "__main__":
+    asyncio.run(run())

src/mcp/client/session.py

@@ -48,6 +48,38 @@ async def __call__(
     ) -> None: ...  # pragma: no branch
 
 
+class ProgressNotificationFnT(Protocol):
+    async def __call__(
+        self,
+        params: types.ProgressNotificationParams,
+    ) -> None: ...
+
+
+class ResourceUpdatedFnT(Protocol):
+    async def __call__(
+        self,
+        params: types.ResourceUpdatedNotificationParams,
+    ) -> None: ...
+
+
+class ResourceListChangedFnT(Protocol):
+    async def __call__(
+        self,
+    ) -> None: ...
+
+
+class ToolListChangedFnT(Protocol):
+    async def __call__(
+        self,
+    ) -> None: ...
+
+
+class PromptListChangedFnT(Protocol):
+    async def __call__(
+        self,
+    ) -> None: ...
+
+
 class MessageHandlerFnT(Protocol):
     async def __call__(
         self,
@@ -96,6 +128,32 @@ async def _default_logging_callback(
     pass
 
 
+async def _default_progress_callback(
+    params: types.ProgressNotificationParams,
+) -> None:
+    """Note: Default progress handling happens in the BaseSession class. This callback will only be called after the
+    default progress handling has completed."""
+    pass
+
+
+async def _default_resource_updated_callback(
+    params: types.ResourceUpdatedNotificationParams,
+) -> None:
+    pass
+
+
+async def _default_resource_list_changed_callback() -> None:
+    pass
+
+
+async def _default_tool_list_changed_callback() -> None:
+    pass
+
+
+async def _default_prompt_list_changed_callback() -> None:
+    pass
+
+
 ClientResponse: TypeAdapter[types.ClientResult | types.ErrorData] = TypeAdapter(types.ClientResult | types.ErrorData)
 
 
@@ -117,6 +175,11 @@ def __init__(
         elicitation_callback: ElicitationFnT | None = None,
         list_roots_callback: ListRootsFnT | None = None,
         logging_callback: LoggingFnT | None = None,
+        progress_notification_callback: ProgressNotificationFnT | None = None,
+        resource_updated_callback: ResourceUpdatedFnT | None = None,
+        resource_list_changed_callback: ResourceListChangedFnT | None = None,
+        tool_list_changed_callback: ToolListChangedFnT | None = None,
+        prompt_list_changed_callback: PromptListChangedFnT | None = None,
         message_handler: MessageHandlerFnT | None = None,
         client_info: types.Implementation | None = None,
     ) -> None:
@@ -132,6 +195,11 @@ def __init__(
         self._elicitation_callback = elicitation_callback or _default_elicitation_callback
         self._list_roots_callback = list_roots_callback or _default_list_roots_callback
         self._logging_callback = logging_callback or _default_logging_callback
+        self._progress_notification_callback = progress_notification_callback or _default_progress_callback
+        self._resource_updated_callback = resource_updated_callback or _default_resource_updated_callback
+        self._resource_list_changed_callback = resource_list_changed_callback or _default_resource_list_changed_callback
+        self._tool_list_changed_callback = tool_list_changed_callback or _default_tool_list_changed_callback
+        self._prompt_list_changed_callback = prompt_list_changed_callback or _default_prompt_list_changed_callback
         self._message_handler = message_handler or _default_message_handler
         self._tool_output_schemas: dict[str, dict[str, Any] | None] = {}
         self._server_capabilities: types.ServerCapabilities | None = None
@@ -547,9 +615,20 @@ async def _handle_incoming(
 
     async def _received_notification(self, notification: types.ServerNotification) -> None:
         """Handle notifications from the server."""
-        # Process specific notification types
         match notification.root:
             case types.LoggingMessageNotification(params=params):
                 await self._logging_callback(params)
+            case types.ProgressNotification(params=params):
+                await self._progress_notification_callback(params)
+            case types.ResourceUpdatedNotification(params=params):
+                await self._resource_updated_callback(params)
+            case types.ResourceListChangedNotification():
+                await self._resource_list_changed_callback()
+            case types.ToolListChangedNotification():
+                await self._tool_list_changed_callback()
+            case types.PromptListChangedNotification():
+                await self._prompt_list_changed_callback()
             case _:
+                # CancelledNotification is handled separately in shared/session.py
+                # and should never reach this point. This case is defensive.
                 pass

src/mcp/shared/memory.py

@@ -13,7 +13,19 @@
 from anyio.streams.memory import MemoryObjectReceiveStream, MemoryObjectSendStream
 
 import mcp.types as types
-from mcp.client.session import ClientSession, ElicitationFnT, ListRootsFnT, LoggingFnT, MessageHandlerFnT, SamplingFnT
+from mcp.client.session import (
+    ClientSession,
+    ElicitationFnT,
+    ListRootsFnT,
+    LoggingFnT,
+    MessageHandlerFnT,
+    ProgressNotificationFnT,
+    PromptListChangedFnT,
+    ResourceListChangedFnT,
+    ResourceUpdatedFnT,
+    SamplingFnT,
+    ToolListChangedFnT,
+)
 from mcp.server import Server
 from mcp.server.fastmcp import FastMCP
 from mcp.shared.message import SessionMessage
@@ -53,6 +65,11 @@ async def create_connected_server_and_client_session(
     sampling_callback: SamplingFnT | None = None,
     list_roots_callback: ListRootsFnT | None = None,
     logging_callback: LoggingFnT | None = None,
+    progress_notification_callback: ProgressNotificationFnT | None = None,
+    resource_updated_callback: ResourceUpdatedFnT | None = None,
+    resource_list_changed_callback: ResourceListChangedFnT | None = None,
+    tool_list_changed_callback: ToolListChangedFnT | None = None,
+    prompt_list_changed_callback: PromptListChangedFnT | None = None,
     message_handler: MessageHandlerFnT | None = None,
     client_info: types.Implementation | None = None,
     raise_exceptions: bool = False,
@@ -88,6 +105,11 @@ async def create_connected_server_and_client_session(
                     sampling_callback=sampling_callback,
                     list_roots_callback=list_roots_callback,
                     logging_callback=logging_callback,
+                    progress_notification_callback=progress_notification_callback,
+                    resource_updated_callback=resource_updated_callback,
+                    resource_list_changed_callback=resource_list_changed_callback,
+                    tool_list_changed_callback=tool_list_changed_callback,
+                    prompt_list_changed_callback=prompt_list_changed_callback,
                     message_handler=message_handler,
                     client_info=client_info,
                     elicitation_callback=elicitation_callback,