BCAC (Business Credit Alliance Chain, Business Credit Chain) builds a new retail commercial credit economic ecology based on blockchain; through blockchain technology, it creates a traceable supply chain, quantifiable credit, open and transparent data, and integrated Consumer shopping, membership service, precision marketing, centralized procurement and other scenarios are integrated to form online e-commerce transactions and offline shopping experience, and build a new retail ecosystem with multi-party participation and multi-party benefits. BCAC is the only value measurement and circulation protocol for the new retail commercial credit economic ecology built by WXChain. All data collection, exchange, and scene applications require BCAC as an interactive medium.