NULS is a blockchain infrastructure for customized services, a global open source community project. NULS adopts the microservices concept to achieve a highly modular underlying architecture, utilizing technologies such as module warehouses, smart contracts, and cross chain. At the same time, combined with the ability of chain factories to quickly build chains, it reduces blockchain development costs and promotes the implementation of blockchain commercial applications. NULS proposes a modular thinking and multi chain parallel microservice architecture, adhering to the development concept of "chain" as the core, and creating a core product "chain factory". Based on NULS, users can flexibly choose core functional modules such as network module, consensus module, storage module, ledger module, and smart contract to create new blockchains in the NULS chain network. They can also define their business logic through smart contracts with minimal programming work....