chore: import upstream snapshot with attribution

examples/stories/reconnect/server_lowlevel.py

@@ -0,0 +1,48 @@
+"""A small modern server whose DiscoverResult a client persists for zero-RTT reconnect (lowlevel API)."""
+
+from typing import Any
+
+import mcp_types as types
+
+from mcp.server.context import ServerRequestContext
+from mcp.server.lowlevel import Server
+from stories._hosting import run_server_from_args
+
+ADD = types.Tool(
+    name="add",
+    description="Add two integers.",
+    input_schema={
+        "type": "object",
+        "properties": {"a": {"type": "integer"}, "b": {"type": "integer"}},
+        "required": ["a", "b"],
+    },
+)
+
+
+def build_server() -> Server[Any]:
+    async def list_tools(
+        ctx: ServerRequestContext[Any], params: types.PaginatedRequestParams | None
+    ) -> types.ListToolsResult:
+        return types.ListToolsResult(tools=[ADD])
+
+    async def call_tool(ctx: ServerRequestContext[Any], params: types.CallToolRequestParams) -> types.CallToolResult:
+        assert params.arguments is not None
+        if params.name == "add":
+            total = int(params.arguments["a"]) + int(params.arguments["b"])
+            return types.CallToolResult(
+                content=[types.TextContent(text=str(total))],
+                structured_content={"result": total},
+            )
+        raise NotImplementedError
+
+    return Server(
+        "reconnect-example",
+        version="1.0.0",
+        instructions="Call add(a, b) to sum two integers.",
+        on_list_tools=list_tools,
+        on_call_tool=call_tool,
+    )
+
+
+if __name__ == "__main__":
+    run_server_from_args(build_server)