Nash chain (nuls) is a blockchain infrastructure for customized services and a global open source community project. Nuls adopts the idea of micro service to achieve a highly modular underlying architecture, and uses technologies such as module warehouse, smart contract and cross chain, combined with the chain factory's ability to quickly build the chain, to reduce the development cost of blockchain and promote the implementation of blockchain commercial applications. Nuls puts forward the micro service architecture of modular thinking and multi chain parallel, adheres to the development concept of "chain" as the core, and creates a "chain factory" for core products. Based on nuls, users can flexibly select core function modules such as network module, consensus module, storage module, ledger module and smart contract to create a new blockchain in the nuls chain network, or define their own business logic through smart contract with little programming work.