import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
import { z } from "zod";
/**
* MCP Server
*/
const server = new McpServer({
name: "Live Weather MCP",
version: "1.2.0",
});
/**
* City → Lat/Lon → Current Weather
*/
async function getWeather(city) {
try {
/* ---------- STEP 1: GEOCODING ---------- */
const geoUrl = `https://geocoding-api.open-meteo.com/v1/search?name=${encodeURIComponent(
city
)}&count=1`;
const geoRes = await fetch(geoUrl);
const geoJson = await geoRes.json();
if (!geoJson.results || geoJson.results.length === 0) {
return null;
}
const {
latitude,
longitude,
name,
country,
admin1,
} = geoJson.results[0];
/* ---------- STEP 2: WEATHER ---------- */
const weatherUrl = `https://api.open-meteo.com/v1/forecast?latitude=${latitude}&longitude=${longitude}¤t_weather=true`;
const weatherRes = await fetch(weatherUrl);
const weatherJson = await weatherRes.json();
if (!weatherJson.current_weather) {
return null;
}
const w = weatherJson.current_weather;
/* ---------- SAFE LOCATION STRING ---------- */
const locationParts = [name];
if (admin1) locationParts.push(admin1);
locationParts.push(country);
return {
location: locationParts.join(", "),
temperature: `${w.temperature}°C`,
wind: `${w.windspeed} km/h`,
rain: w.weathercode >= 51 ? "Rain expected" : "No rain expected",
forecast:
w.weathercode === 0
? "Clear sky"
: w.weathercode < 3
? "Partly cloudy"
: w.weathercode < 50
? "Cloudy"
: "Rainy",
time: w.time,
};
} catch (err) {
console.error("Weather fetch error:", err);
return null;
}
}
/**
* Question → Answer
*/
function answerQuestion(weather, question) {
const q = question.toLowerCase();
if (q.includes("temperature") || q.includes("temp")) {
return `🌡 Temperature in ${weather.location}: ${weather.temperature}`;
}
if (q.includes("rain")) {
return `🌧 Rain status in ${weather.location}: ${weather.rain}`;
}
if (q.includes("wind")) {
return `🌬 Wind speed in ${weather.location}: ${weather.wind}`;
}
if (q.includes("forecast")) {
return `📢 Forecast for ${weather.location}: ${weather.forecast}`;
}
return `
📍 Location: ${weather.location}
🕒 Time: ${weather.time}
🌡 Temperature: ${weather.temperature}
📢 Forecast: ${weather.forecast}
🌧 Rain: ${weather.rain}
🌬 Wind: ${weather.wind}
`;
}
/**
* MCP Tool
*/
server.tool(
"askWeather",
{
city: z.string(),
question: z.string(),
},
async ({ city, question }) => {
const weather = await getWeather(city);
if (!weather) {
return {
content: [
{
type: "text",
text: `❌ Weather data not available for "${city}".`,
},
],
};
}
return {
content: [{ type: "text", text: answerQuestion(weather, question) }],
};
}
);
/**
* Start MCP
*/
async function start() {
const transport = new StdioServerTransport();
await server.connect(transport);
}
start();
