feat: Add support for specifying NotificationOptions in FastMCP and lowlevel Server creation

Author: daamitt

README.md

@@ -833,9 +833,13 @@ Tools can send logs and notifications through the context:
 <!-- snippet-source examples/snippets/servers/notifications.py -->
 ```python
 from mcp.server.fastmcp import Context, FastMCP
+from mcp.server.lowlevel.server import NotificationOptions
 from mcp.server.session import ServerSession
 
-mcp = FastMCP(name="Notifications Example")
+# Setup Server Capabilities
+notification_options = NotificationOptions(prompts_changed=False, resources_changed=True, tools_changed=False)
+
+mcp = FastMCP(name="Notifications Example", notification_options=notification_options)
 
 
 @mcp.tool()

examples/snippets/servers/notifications.py

@@ -1,7 +1,11 @@
 from mcp.server.fastmcp import Context, FastMCP
+from mcp.server.lowlevel.server import NotificationOptions
 from mcp.server.session import ServerSession
 
-mcp = FastMCP(name="Notifications Example")
+# Setup Server Capabilities
+notification_options = NotificationOptions(prompts_changed=False, resources_changed=True, tools_changed=False)
+
+mcp = FastMCP(name="Notifications Example", notification_options=notification_options)
 
 
 @mcp.tool()

src/mcp/server/fastmcp/server.py

@@ -33,7 +33,7 @@
 from mcp.server.fastmcp.utilities.context_injection import find_context_parameter
 from mcp.server.fastmcp.utilities.logging import configure_logging, get_logger
 from mcp.server.lowlevel.helper_types import ReadResourceContents
-from mcp.server.lowlevel.server import LifespanResultT
+from mcp.server.lowlevel.server import LifespanResultT, NotificationOptions
 from mcp.server.lowlevel.server import Server as MCPServer
 from mcp.server.lowlevel.server import lifespan as default_lifespan
 from mcp.server.session import ServerSession, ServerSessionT
@@ -148,6 +148,7 @@ def __init__(  # noqa: PLR0913
         lifespan: Callable[[FastMCP[LifespanResultT]], AbstractAsyncContextManager[LifespanResultT]] | None = None,
         auth: AuthSettings | None = None,
         transport_security: TransportSecuritySettings | None = None,
+        notification_options: NotificationOptions | None = None,
     ):
         self.settings = Settings(
             debug=debug,
@@ -177,6 +178,7 @@ def __init__(  # noqa: PLR0913
             # TODO(Marcelo): It seems there's a type mismatch between the lifespan type from an FastMCP and Server.
             # We need to create a Lifespan type that is a generic on the server type, like Starlette does.
             lifespan=(lifespan_wrapper(self, self.settings.lifespan) if self.settings.lifespan else default_lifespan),  # type: ignore
+            notification_options=notification_options,
         )
         self._tool_manager = ToolManager(tools=tools, warn_on_duplicate_tools=self.settings.warn_on_duplicate_tools)
         self._resource_manager = ResourceManager(warn_on_duplicate_resources=self.settings.warn_on_duplicate_resources)

src/mcp/server/lowlevel/server.py

@@ -142,10 +142,12 @@ def __init__(
             [Server[LifespanResultT, RequestT]],
             AbstractAsyncContextManager[LifespanResultT],
         ] = lifespan,
+        notification_options: NotificationOptions | None = None,
     ):
         self.name = name
         self.version = version
         self.instructions = instructions
+        self.notification_options = notification_options or NotificationOptions()
         self.website_url = website_url
         self.icons = icons
         self.lifespan = lifespan
@@ -177,7 +179,7 @@ def pkg_version(package: str) -> str:
             server_name=self.name,
             server_version=self.version if self.version else pkg_version("mcp"),
             capabilities=self.get_capabilities(
-                notification_options or NotificationOptions(),
+                notification_options or self.notification_options,
                 experimental_capabilities or {},
             ),
             instructions=self.instructions,