LocalTides MCP Server

Instructions

Implementation Reference

• src/services/moon-phase-service.ts:55-82 (handler)

  Core handler function that computes moon phases over a date range by iterating daily and calling getMoonPhase.

  getMoonPhasesRange(params: MoonPhasesRangeParams): MoonPhaseInfo[] {
    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: MoonPhaseInfo[] = [];
    const currentDate = new Date(startDate);
    
    while (currentDate <= endDate) {
      result.push(this.getMoonPhase({
        date: currentDate.toISOString().split('T')[0],
        latitude: params.latitude,
        longitude: params.longitude
      }));
      
      // Move to next day
      currentDate.setDate(currentDate.getDate() + 1);
    }
    
    return result;
  }

• src/tools/moon-tools.ts:35-55 (registration)

  Tool registration in FastMCP server, including name, description, input schema, and execute handler that wraps the service call and handles formatting/errors.

  server.addTool({
    name: 'get_moon_phases_range',
    description: 'Get moon phase information for a date range',
    parameters: MoonPhasesRangeParamsSchema,
    execute: async (params) => {
      try {
        const results = moonPhaseService.getMoonPhasesRange(params);
        if (params.format === 'text') {
          return results.map(result => 
            `${result.date}: ${result.phaseName} (${(result.illumination * 100).toFixed(1)}% illuminated)`
          ).join('\n');
        }
        return JSON.stringify(results);
      } catch (error) {
        if (error instanceof Error) {
          throw new Error(`Failed to get moon phases: ${error.message}`);
        }
        throw new Error('Failed to get moon phases');
      }
    }
  });

• src/interfaces/moon.ts:19-25 (schema)

  Zod schema defining the input parameters for the get_moon_phases_range tool.

  export const MoonPhasesRangeParamsSchema = 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).optional().describe('Latitude for location-specific calculations'),
    longitude: z.number().min(-180).max(180).optional().describe('Longitude for location-specific calculations'),
    format: z.enum(['json', 'text']).optional().describe('Output format (json or text)')
  });