SAT is a decentralized application platform. It provides a series of SDKs and APIs to help developers build decentralized applications based on Javascript and side chain technology, allowing developers to use it easily and safely. Using the SAT ecosystem, developers can quickly iterate their Javascript applications, and Published to the system's built-in application store, these applications can be used by the platform and serve ordinary users, and the entire process is guaranteed by the credit-safe SAT consensus network. The distributed nodes in the process are downloaded and executed. The SAT system itself is also a completely open and decentralized application with built-in tokens. It can interact with Start chain or Dapp through two-way wedge, as a bridge and medium for asset conversion between all Dapps.