SardineChain (Sardine Chain) has new digital asset issuance requirements for different application platforms. It uses SDE as the underlying digital asset issuance and circulation support, and supports the digital asset issuance of various Tokens through smart contracts and bank gateways. The issuance of various Tokens is based on the IOU model. The role of the native currency SDE: 1. Prevent network dust attacks; 2. Handling fees for asset transactions; 3. Dividends for income rights assets; 4. Deposit for ecological participation. Each transaction will consume a little SDE as a network fee, about 0.0001SDE. The busier the network is, the more network fees are required each time, and the network fees consumed will flow back to the community. The more SDE incentives are given to those who contribute more to the ecology, encouraging pioneers who contribute more to the community.