Distributed Storage and Retrieval: as a fundamental capability of decentralized storage, data should be persistently stored on the network and ensure permanent availability. In addition, the CATA protocol guarantees high storage performance, supports reading and writing large amounts of data, and achieves practical cost. Compared to cold storage, CATA puts more design energy on retrieval and supports content-based flexible queries (instead of just file download) to meet fine-grained data organization requirements (e.g., NFT classification retrieval).