Weather MCP Server example

index.ts

import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
import { z } from "zod";

const server = new McpServer({
	name: "Weather server",
	version: "1.0.0",
});

server.tool(
	"getWeather",
	"Gets the weather in a city",
	{
		city: z.string(),
	},
	async ({ city }) => {
		return {
			content: [
				{
					type: "text",
					text: "It's sunny in " + city + " today!",
				},
			],
		};
	},
);

const transport = new StdioServerTransport();
await server.connect(transport).catch(console.error);

This is a single-file MCP server implementation following this tutorial
https://www.aihero.dev/mcp-server-from-a-single-typescript-file