LocalTides MCP Server

Instructions

Implementation Reference

• src/services/sun-service.ts:70-98 (handler)

  Core implementation of getSunTimesRange that computes sun times over a date range using SunCalc library, looping daily and calling getSunTimes.

  getSunTimesRange(params: SunTimesRangeParams): SunTimesInfo[] {
    const startDate = new Date(params.start_date);
    const endDate = new Date(params.end_date);
    
    if (isNaN(startDate.getTime()) || isNaN(endDate.getTime())) {
      throw new Error('Invalid date format. Please use YYYY-MM-DD format.');
    }
    
    if (startDate > endDate) {
      throw new Error('Start date must be before end date.');
    }
    
    const result: SunTimesInfo[] = [];
    const currentDate = new Date(startDate);
    
    while (currentDate <= endDate) {
      result.push(this.getSunTimes({
        date: currentDate.toISOString().split('T')[0],
        latitude: params.latitude,
        longitude: params.longitude,
        timezone: params.timezone
      }));
      
      // Move to next day
      currentDate.setDate(currentDate.getDate() + 1);
    }
    
    return result;
  }

• src/interfaces/sun.ts:20-29 (schema)

  Zod schema definition for the input parameters of the get_sun_times_range tool.

  export const SunTimesRangeParamsSchema = z.object({
    start_date: z.string().describe('Start date (YYYY-MM-DD format)'),
    end_date: z.string().describe('End date (YYYY-MM-DD format)'),
    latitude: z.number().min(-90).max(90).describe('Latitude for location-specific calculations'),
    longitude: z.number().min(-180).max(180).describe('Longitude for location-specific calculations'),
    format: z.enum(['json', 'text']).optional().describe('Output format (json or text)'),
    timezone: z.string().optional().describe('Timezone for the results. Defaults to UTC.')
  });
  
  export type SunTimesRangeParams = z.infer<typeof SunTimesRangeParamsSchema>;

• src/tools/sun-tools.ts:43-70 (registration)

  MCP tool registration for 'get_sun_times_range', including description, input schema reference, and execute handler that delegates to SunService.

  server.addTool({
    name: 'get_sun_times_range',
    description: 'Get sun rise/set and other sun event times for a date range and location',
    parameters: SunTimesRangeParamsSchema,
    execute: async (params) => {
      try {
        const results = sunService.getSunTimesRange(params);
        if (params.format === 'text') {
          let text = `Sun times from ${params.start_date} to ${params.end_date} at latitude ${params.latitude}, longitude ${params.longitude}:\n\n`;
          
          results.forEach(result => {
            text += `Date: ${result.date}\n`;
            text += `Sunrise: ${result.sunrise || 'N/A'}\n`;
            text += `Sunset: ${result.sunset || 'N/A'}\n`;
            text += `Day length: ${Math.floor(result.dayLength / 60)}h ${Math.round(result.dayLength % 60)}m\n\n`;
          });
          
          return text;
        }
        return JSON.stringify(results);
      } catch (error) {
        if (error instanceof Error) {
          throw new Error(`Failed to get sun times range: ${error.message}`);
        }
        throw new Error('Failed to get sun times range');
      }
    }
  });