{"message":"SMS Sampling System API v2.0","version":"2.0.0","features":["PostgreSQL database with encryption","Store management and code mapping","Image confirmation support","Data retention and GDPR compliance","Authentication and access controls"],"endpoints":{"POST /webhook/sms":"Twilio SMS webhook","POST /auth/login":"Admin authentication","GET /api/admin/stats":"Campaign statistics","GET /api/admin/stores":"Store management","POST /api/admin/codes":"Add codes to campaign","GET /api/admin/submissions":"Get recent submissions","POST /api/admin/upload":"File upload","GET /admin":"Admin dashboard"}}