Smart Application Chain (SAC for short) is the basic currency in the smart application chain ecosystem, which can circulate in the SAC ecosystem. SAC Unicom connects all applications based on the SAC smart application chain, breaks through the value islands between applications, and builds a blueprint for the future blockchain smart economy. As a decentralized digital cryptocurrency, it is specially designed for SAC ecological applications. SAC Smart Application Chain aims to create a developer-friendly public link access system, providing developers with a complete KYC tool, user system, and application management suite.