Japanese Weather MCP Server

Instructions

Implementation Reference

• src/server.ts:98-110 (handler)

  The main handler function for the 'get_available_city_ids' tool. It iterates over CITY_IDS and formats a string listing all available city IDs.

  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;
  },

• src/server.ts:91-113 (registration)

  Registration of the 'get_available_city_ids' tool using FastMCP's server.addTool method, including name, description, annotations, parameters schema, and inline handler.

  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({}),
  });

• src/server.ts:112-112 (schema)

  Input schema for the tool, defined as an empty object using Zod (no parameters required).

  parameters: z.object({}),

• src/weather-api.ts:135-156 (helper)

  Constant object CITY_IDS containing predefined city names and their corresponding IDs, used by the tool handler to generate the list of available cities.

  export const CITY_IDS = {
    // Fukuoka
    FUKUOKA: "400010",
    // Hiroshima
    HIROSHIMA: "340010",
    // Kawasaki
    KAWASAKI: "140020",
    // Kobe
    KOBE: "280010",
    // Kyoto
    KYOTO: "260010",
    // Nagoya
    NAGOYA: "230010",
    // Osaka
    OSAKA: "270000",
    // Sapporo
    SAPPORO: "016010",
    // Tokyo
    TOKYO: "130010",
    // Yokohama
    YOKOHAMA: "140010",
  } as const;