MCP Weather Server Demo

import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js' import { StdioServerTransport } from '@modelcontextprotocol/sdk/server/stdio.js' import { z } from 'zod' // 1.- Create server. // Main interface for the MCP server. // It manages the tools, connections, and interactions with clients. const server = new McpServer({ name: "Demo", version: "1.0.0" }) // 2.- Set tools. // Tools are functions that can be called by clients to perform specific tasks. // In this case, we create a tool to fetch the weather of a city. server.tool( 'fetch-weather', // titulo de la herramienta 'Tool to fetch the weather of a City', { city: z.string().describe('City name') }, async({city}) =>{ const response = await fetch(`https://geocoding-api.open-meteo.com/v1/search?name=${city}&count=10&language=en&format=json`) const data = await response.json() if (data.length === 0){ return { content: [ { type: 'text', text: `No info for ${city}` } ] } } const { latitude, longitude } = data.results[0] const weatherResponse = await fetch(`https://api.open-meteo.com/v1/forecast?latitude=${latitude}&longitude=${longitude}&hourly=temperature_2m&current=temperature_2m,precipitation,is_day`) const weatherData = await weatherResponse.json() return { content: [ { type: 'text', text: JSON.stringify(weatherData, null, 2) } ] } } ) // 3.- Listen for connections. // The server listens for incoming connections from clients. // In this case, we use a StdioServerTransport to communicate via standard input/output. const transport = new StdioServerTransport() await server.connect(transport)