chore: import upstream snapshot with attribution

examples/stories/sampling/server.py

@@ -0,0 +1,25 @@
+"""Sampling primitive: a tool asks the client's LLM for a completion mid-call."""
+
+from mcp_types import SamplingMessage, TextContent
+
+from mcp.server.mcpserver import Context, MCPServer
+from stories._hosting import run_server_from_args
+
+
+def build_server() -> MCPServer:
+    mcp = MCPServer("sampling-example")
+
+    @mcp.tool(description="Summarize text by asking the host's LLM via sampling/createMessage.")
+    async def summarize(text: str, ctx: Context) -> str:
+        result = await ctx.session.create_message(  # pyright: ignore[reportDeprecated]
+            messages=[SamplingMessage(role="user", content=TextContent(text=f"Summarize in one sentence:\n\n{text}"))],
+            max_tokens=200,
+        )
+        assert isinstance(result.content, TextContent)
+        return result.content.text
+
+    return mcp
+
+
+if __name__ == "__main__":
+    run_server_from_args(build_server)