AI MCP ServiceNow

Instructions

Implementation Reference

• main.ts:43-59 (registration)

  Registration of the 'get-weather' tool using McpServer.tool, including name, description, input schema, and handler.

  server.tool(
      'get-weather',
      'Tool to get the weather of a city',
      {
          city: z.string().describe("The name of the city to get the weather for")
      },
      async ({ city }) => {
          return {
              content: [
                  {
                      type: "text",
                      text: await getWeather({ city })
                  }
              ]
          }
      }
  );

• main.ts:49-59 (handler)

  The MCP tool handler function that invokes the getWeather helper and returns formatted text content.

      async ({ city }) => {
          return {
              content: [
                  {
                      type: "text",
                      text: await getWeather({ city })
                  }
              ]
          }
      }
  );

• main.ts:46-48 (schema)

  Zod input schema defining the 'city' parameter as a string.

  {
      city: z.string().describe("The name of the city to get the weather for")
  },

• tools/get-weather.js:1-25 (helper)

  Helper function implementing the core weather fetching logic using Open-Meteo APIs for geocoding and forecast data.

  export default async ({ city }) => {
      try {
          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.results || data.results.length === 0) {
              return `No results found for city: ${city}`;
          }
          let firstResult = data.results[0];
          const { latitude, longitude } = firstResult;
          //return `Coordinates for ${city}: Latitude: ${latitude}, Longitude: ${longitude}`;
          const weatherResponse = await fetch(`https://api.open-meteo.com/v1/forecast?latitude=${latitude}&longitude=${longitude}&hourly=temperature_2m,precipitation,apparent_temperature,relative_humidity_2m&forecast_days=1`);
          if (!weatherResponse.ok) {
              return `Error fetching weather data: ${weatherResponse.statusText}`;
          }
          return `Weather data for ${city}:\n` +
              `Latitude: ${latitude}, Longitude: ${longitude}\n` +
              `Weather: ${JSON.stringify(await weatherResponse.json(), null, 2)}`;
  
          const weatherData = await weatherResponse.json();
  
          return JSON.stringify(weatherData, null, 2);
      } catch (error) {
          return `Error fetching weather data: ${error.message}`;
      }
  }