This case study describes Singpass, Singapore's national digital identity (NDI), and API Exchange (APEX), the government's data-sharing platform. It highlights not just how they work but also how they work together. Built by the Government Technology Agency of Singapore (GovTech), both products have helped to improve the lives of Singaporeans and residents, and to enable government agencies and businesses to offer better services. This has contributed greatly to Singapore becoming a leading digital government, economy, and society, which are the three pillars of its Smart Nation Initiative.