{"success":true,"message":"Clients API - Invoice Management System","version":"1.0.0","authentication":{"required":true,"method":"API Key","header":"apikey"},"endpoints":{"health":"/api/health","overdueClients":"/api/clients/overdue","clientsDueNext6Days":"/api/clients/due-next-6-days","allClients":"/api/clients","statistics":"/api/clients/statistics"},"timestamp":"2026-04-28T01:51:42.125Z"}