refactor: replace lowlevel Server decorators with on_* constructor kwargs (#1985)

examples/servers/simple-streamablehttp-stateless/mcp_simple_streamablehttp_stateless/server.py

@@ -1,13 +1,12 @@
 import contextlib
 import logging
 from collections.abc import AsyncIterator
-from typing import Any
 
 import anyio
 import click
 import uvicorn
 from mcp import types
-from mcp.server.lowlevel import Server
+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
@@ -17,6 +16,64 @@ from starlette.types import Receive, Scope, Send
 logger = logging.getLogger(__name__)
 
 
+async def handle_list_tools(
+    ctx: ServerRequestContext, params: types.PaginatedRequestParams | None
+) -> types.ListToolsResult:
+    return types.ListToolsResult(
+        tools=[
+            types.Tool(
+                name="start-notification-stream",
+                description=("Sends a stream of notifications with configurable count and interval"),
+                input_schema={
+                    "type": "object",
+                    "required": ["interval", "count", "caller"],
+                    "properties": {
+                        "interval": {
+                            "type": "number",
+                            "description": "Interval between notifications in seconds",
+                        },
+                        "count": {
+                            "type": "number",
+                            "description": "Number of notifications to send",
+                        },
+                        "caller": {
+                            "type": "string",
+                            "description": ("Identifier of the caller to include in notifications"),
+                        },
+                    },
+                },
+            )
+        ]
+    )
+
+
+async def handle_call_tool(ctx: ServerRequestContext, params: types.CallToolRequestParams) -> types.CallToolResult:
+    arguments = params.arguments or {}
+    interval = arguments.get("interval", 1.0)
+    count = arguments.get("count", 5)
+    caller = arguments.get("caller", "unknown")
+
+    # Send the specified number of notifications with the given interval
+    for i in range(count):
+        await ctx.session.send_log_message(
+            level="info",
+            data=f"Notification {i + 1}/{count} from caller: {caller}",
+            logger="notification_stream",
+            related_request_id=ctx.request_id,
+        )
+        if i < count - 1:  # Don't wait after the last notification
+            await anyio.sleep(interval)
+
+    return types.CallToolResult(
+        content=[
+            types.TextContent(
+                type="text",
+                text=(f"Sent {count} notifications with {interval}s interval for caller: {caller}"),
+            )
+        ]
+    )
+
+
 @click.command()
 @click.option("--port", default=3000, help="Port to listen on for HTTP")
 @click.option(
@@ -41,59 +98,11 @@ def main(
         format="%(asctime)s - %(name)s - %(levelname)s - %(message)s",
     )
 
-    app = Server("mcp-streamable-http-stateless-demo")
-
-    @app.call_tool()
-    async def call_tool(name: str, arguments: dict[str, Any]) -> list[types.ContentBlock]:
-        ctx = app.request_context
-        interval = arguments.get("interval", 1.0)
-        count = arguments.get("count", 5)
-        caller = arguments.get("caller", "unknown")
-
-        # Send the specified number of notifications with the given interval
-        for i in range(count):
-            await ctx.session.send_log_message(
-                level="info",
-                data=f"Notification {i + 1}/{count} from caller: {caller}",
-                logger="notification_stream",
-                related_request_id=ctx.request_id,
-            )
-            if i < count - 1:  # Don't wait after the last notification
-                await anyio.sleep(interval)
-
-        return [
-            types.TextContent(
-                type="text",
-                text=(f"Sent {count} notifications with {interval}s interval for caller: {caller}"),
-            )
-        ]
-
-    @app.list_tools()
-    async def list_tools() -> list[types.Tool]:
-        return [
-            types.Tool(
-                name="start-notification-stream",
-                description=("Sends a stream of notifications with configurable count and interval"),
-                input_schema={
-                    "type": "object",
-                    "required": ["interval", "count", "caller"],
-                    "properties": {
-                        "interval": {
-                            "type": "number",
-                            "description": "Interval between notifications in seconds",
-                        },
-                        "count": {
-                            "type": "number",
-                            "description": "Number of notifications to send",
-                        },
-                        "caller": {
-                            "type": "string",
-                            "description": ("Identifier of the caller to include in notifications"),
-                        },
-                    },
-                },
-            )
-        ]
+    app = Server(
+        "mcp-streamable-http-stateless-demo",
+        on_list_tools=handle_list_tools,
+        on_call_tool=handle_call_tool,
+    )
 
     # Create the session manager with true stateless mode
     session_manager = StreamableHTTPSessionManager(