chore: import upstream snapshot with attribution

examples/stories/schema_validators/server_lowlevel.py

@@ -0,0 +1,55 @@
+"""Same four tools via lowlevel.Server — inputSchema is hand-written JSON Schema."""
+
+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
+
+# With lowlevel.Server there is no reflection layer: you author the JSON Schema
+# yourself and validate/unpack `params.arguments` in the handler.
+PERSON_SCHEMA: dict[str, Any] = {
+    "type": "object",
+    "properties": {"name": {"type": "string"}, "title": {"type": "string"}},
+    "required": ["name"],
+}
+TOOLS = [
+    types.Tool(
+        name=f"greet_{variant}",
+        description=f"Greet ({variant} input shape)",
+        input_schema={"type": "object", "properties": {"who": PERSON_SCHEMA}, "required": ["who"]},
+    )
+    for variant in ("pydantic", "typeddict", "dataclass")
+]
+TOOLS.append(
+    types.Tool(
+        name="greet_dict",
+        description="Greet (free-form dict input)",
+        input_schema={
+            "type": "object",
+            "properties": {"who": {"type": "object", "additionalProperties": True}},
+            "required": ["who"],
+        },
+    )
+)
+
+
+def build_server() -> Server[Any]:
+    async def list_tools(
+        ctx: ServerRequestContext[Any], params: types.PaginatedRequestParams | None
+    ) -> types.ListToolsResult:
+        return types.ListToolsResult(tools=TOOLS)
+
+    async def call_tool(ctx: ServerRequestContext[Any], params: types.CallToolRequestParams) -> types.CallToolResult:
+        assert params.arguments is not None
+        who = params.arguments["who"]
+        text = f"Hello {who['name']}, my {who.get('title', 'friend')}"
+        return types.CallToolResult(content=[types.TextContent(text=text)])
+
+    return Server("schema-validators-example", on_list_tools=list_tools, on_call_tool=call_tool)
+
+
+if __name__ == "__main__":
+    run_server_from_args(build_server)