Tagger is a full-stack AI data solutions platform that establishes a cross-border data authentication protocol. It creates a permissionless hub for data collection, labeling, management, and trading. The platform leverages Web 3's crowdsourcing advantages for data labeling and collection and utilizes blockchain technology to form a permissionless data authentication and trading system. This addresses the prevalent issues of data silos, data authentication chaos, and the lack of professional annotators in the current data landscape.