import { FastMCP } from "fastmcp";
import { z } from "zod";
import { CITY_IDS, WeatherAPI } from "./weather-api.js";
const weatherAPI = new WeatherAPI();
const server = new FastMCP({
name: "Japanese Weather API",
version: "1.0.0",
});
// Tool to get weather forecast for a specific city
server.addTool({
annotations: {
openWorldHint: true, // This tool interacts with external weather API
readOnlyHint: true, // This tool doesn't modify anything
title: "Get Weather Forecast",
},
description: "Get weather forecast for a Japanese city using city ID",
execute: async (args) => {
try {
const forecast = await weatherAPI.getWeatherForecast(args.cityId);
// Format the response in a readable way
const today = forecast.forecasts[0];
const tomorrow = forecast.forecasts[1];
const dayAfter = forecast.forecasts[2];
let result = `🌤️ Weather Forecast for ${forecast.location.prefecture} ${forecast.location.city}\n`;
result += `📅 Published: ${forecast.publicTimeFormatted}\n`;
result += `🏢 Office: ${forecast.publishingOffice}\n\n`;
// Today's forecast
result += `📅 Today (${today.dateLabel}):\n`;
result += ` Weather: ${today.telop}\n`;
result += ` Max Temp: ${today.temperature.max.celsius || "N/A"}°C\n`;
result += ` Min Temp: ${today.temperature.min.celsius || "N/A"}°C\n`;
result += ` Rain Chance: ${today.chanceOfRain.T06_12} (6-12h), ${today.chanceOfRain.T12_18} (12-18h)\n`;
if (today.detail.weather) {
result += ` Details: ${today.detail.weather}\n`;
}
if (today.detail.wind) {
result += ` Wind: ${today.detail.wind}\n`;
}
result += "\n";
// Tomorrow's forecast
result += `📅 Tomorrow (${tomorrow.dateLabel}):\n`;
result += ` Weather: ${tomorrow.telop}\n`;
result += ` Max Temp: ${tomorrow.temperature.max.celsius || "N/A"}°C\n`;
result += ` Min Temp: ${tomorrow.temperature.min.celsius || "N/A"}°C\n`;
result += ` Rain Chance: ${tomorrow.chanceOfRain.T06_12} (6-12h), ${tomorrow.chanceOfRain.T12_18} (12-18h)\n`;
if (tomorrow.detail.weather) {
result += ` Details: ${tomorrow.detail.weather}\n`;
}
if (tomorrow.detail.wind) {
result += ` Wind: ${tomorrow.detail.wind}\n`;
}
result += "\n";
// Day after tomorrow's forecast
result += `📅 Day After Tomorrow (${dayAfter.dateLabel}):\n`;
result += ` Weather: ${dayAfter.telop}\n`;
result += ` Max Temp: ${dayAfter.temperature.max.celsius || "N/A"}°C\n`;
result += ` Min Temp: ${dayAfter.temperature.min.celsius || "N/A"}°C\n`;
result += ` Rain Chance: ${dayAfter.chanceOfRain.T06_12} (6-12h), ${dayAfter.chanceOfRain.T12_18} (12-18h)\n`;
if (dayAfter.detail.weather) {
result += ` Details: ${dayAfter.detail.weather}\n`;
}
if (dayAfter.detail.wind) {
result += ` Wind: ${dayAfter.detail.wind}\n`;
}
return result;
} catch (error) {
return `Error fetching weather data: ${error instanceof Error ? error.message : "Unknown error"}`;
}
},
name: "get_weather_forecast",
parameters: z.object({
cityId: z
.string()
.describe(
"City ID for the Japanese city (e.g., '130010' for Tokyo, '270000' for Osaka)",
),
}),
});
// Tool to get available city IDs
server.addTool({
annotations: {
openWorldHint: false, // This tool doesn't interact with external systems
readOnlyHint: true, // This tool doesn't modify anything
title: "Get Available City IDs",
},
description: "Get a list of available city IDs for Japanese cities",
execute: async () => {
let result = "🏙️ Available Japanese City IDs:\n\n";
Object.entries(CITY_IDS).forEach(([name, id]) => {
result += `${name}: ${id}\n`;
});
result += "\n💡 You can use these IDs with the get_weather_forecast tool.";
result +=
"\n📖 For more city IDs, visit: https://weather.tsukumijima.net/primary_area.xml";
return result;
},
name: "get_available_city_ids",
parameters: z.object({}),
});
// Tool to get weather forecast by city name (using common cities)
server.addTool({
annotations: {
openWorldHint: true, // This tool interacts with external weather API
readOnlyHint: true, // This tool doesn't modify anything
title: "Get Weather by City Name",
},
description: "Get weather forecast for common Japanese cities by name",
execute: async (args) => {
try {
const cityId =
CITY_IDS[args.cityName.toUpperCase() as keyof typeof CITY_IDS];
if (!cityId) {
const availableCities = Object.keys(CITY_IDS).join(", ");
return `City '${args.cityName}' not found. Available cities: ${availableCities}`;
}
const forecast = await weatherAPI.getWeatherForecast(cityId);
// Format the response in a readable way
const today = forecast.forecasts[0];
let result = `🌤️ Weather for ${forecast.location.prefecture} ${forecast.location.city}\n`;
result += `📅 Published: ${forecast.publicTimeFormatted}\n\n`;
result += `📅 Today:\n`;
result += ` Weather: ${today.telop}\n`;
result += ` Max Temp: ${today.temperature.max.celsius || "N/A"}°C\n`;
result += ` Min Temp: ${today.temperature.min.celsius || "N/A"}°C\n`;
result += ` Rain Chance: ${today.chanceOfRain.T06_12} (6-12h), ${today.chanceOfRain.T12_18} (12-18h)\n`;
if (today.detail.weather) {
result += ` Details: ${today.detail.weather}\n`;
}
if (today.detail.wind) {
result += ` Wind: ${today.detail.wind}\n`;
}
return result;
} catch (error) {
return `Error fetching weather data: ${error instanceof Error ? error.message : "Unknown error"}`;
}
},
name: "get_weather_by_city_name",
parameters: z.object({
cityName: z
.enum([
"TOKYO",
"OSAKA",
"KYOTO",
"FUKUOKA",
"SAPPORO",
"NAGOYA",
"YOKOHAMA",
"KOBE",
"KAWASAKI",
"HIROSHIMA",
])
.describe("Name of the Japanese city"),
}),
});
// Resource for weather API documentation
server.addResource({
async load() {
return {
text: `Japanese Weather API Documentation
This MCP server provides access to Japanese weather forecasts using the weather.tsukumijima.net API.
Available Tools:
1. get_weather_forecast - Get weather forecast using city ID
2. get_available_city_ids - List available city IDs
3. get_weather_by_city_name - Get weather for common cities by name
Common City IDs:
- Tokyo: 130010
- Osaka: 270000
- Kyoto: 260010
- Fukuoka: 400010
- Sapporo: 016010
- Nagoya: 230010
- Yokohama: 140010
- Kobe: 280010
- Kawasaki: 140020
- Hiroshima: 340010
For more city IDs, visit: https://weather.tsukumijima.net/primary_area.xml
API Source: https://weather.tsukumijima.net/
Data provided by: Japan Meteorological Agency`,
};
},
mimeType: "text/plain",
name: "Weather API Documentation",
uri: "file:///docs/weather-api.txt",
});
// Prompt for weather-related queries
server.addPrompt({
arguments: [
{
description: "City name or location for weather information",
name: "location",
required: true,
},
],
description: "Generate a weather forecast request",
load: async (args) => {
return `Please provide weather information for ${args.location}.
You can use the following tools:
1. get_weather_by_city_name - for common Japanese cities
2. get_weather_forecast - for any city using its ID
3. get_available_city_ids - to see available city options
If you need a specific city ID, you can check the available options first.`;
},
name: "weather-forecast",
});
server.start({
transportType: "stdio",
});
