TypeScript MCP Server Template

Instructions

Implementation Reference

• src/plugins/weatherPlugin.ts:24-41 (handler)

  The core handler function for the getWeatherForecast tool. Validates input arguments using WeatherForecastSchema and simulates a weather API call to return formatted forecast data.

  async (args: { [x: string]: any }) => {
    const { latitude, longitude }: WeatherForecastArgs = validateToolArgs(
      WeatherForecastSchema,
      args
    );
  
    // Simulate weather API call (replace with actual API)
    const forecast = await simulateWeatherAPI(latitude, longitude);
  
    return {
      content: [
        {
          type: 'text',
          text: `Weather forecast for coordinates (${latitude}, ${longitude}):\n${forecast}`,
        },
      ],
    };
  }

• src/schemas/toolSchemas.ts:46-49 (schema)

  Zod schema defining the input parameters for getWeatherForecast: latitude and longitude numbers (referencing common schemas).

  export const WeatherForecastSchema = z.object({
    latitude: LatitudeSchema,
    longitude: LongitudeSchema,
  });

• src/plugins/weatherPlugin.ts:17-42 (registration)

  Tool registration call within registerWeatherTools function, including name, metadata, and inline handler. Called from src/server.ts.

  server.registerTool(
    'getWeatherForecast',
    {
      title: 'Get Weather Forecast',
      description:
        'Get weather forecast for a specific location using coordinates',
    },
    async (args: { [x: string]: any }) => {
      const { latitude, longitude }: WeatherForecastArgs = validateToolArgs(
        WeatherForecastSchema,
        args
      );
  
      // Simulate weather API call (replace with actual API)
      const forecast = await simulateWeatherAPI(latitude, longitude);
  
      return {
        content: [
          {
            type: 'text',
            text: `Weather forecast for coordinates (${latitude}, ${longitude}):\n${forecast}`,
          },
        ],
      };
    }
  );

• src/plugins/weatherPlugin.ts:76-96 (helper)

  Helper function simulating a weather API call, generating mock forecast data including temperature, conditions, and location info.

  async function simulateWeatherAPI(
    latitude: number,
    longitude: number
  ): Promise<string> {
    // Simulate API delay
    await new Promise(resolve => setTimeout(resolve, 100));
  
    // Generate mock forecast based on coordinates
    const temperature = Math.round(
      20 + latitude * 0.5 + (Math.random() * 10 - 5)
    );
    const conditions = ['Sunny', 'Cloudy', 'Rainy', 'Partly Cloudy'];
    const condition = conditions[Math.floor(Math.random() * conditions.length)];
  
    return `
  🌤️  Current Conditions: ${condition}
  🌡️  Temperature: ${temperature}°C
          Location: ${latitude.toFixed(4)}, ${longitude.toFixed(4)}
  ⏰ Updated: ${new Date().toLocaleString()}
    `.trim();
  }