Anthropic's biology team has, for the first time, used Claude to resolve the three-dimensional structure of a prokaryotic vault (vault particle). Since this vesicle-like complex was discovered in 1986, its role in living cells had long remained unclear. The team screened homologs from 15 billion predicted sequences and, through laboratory validation, confirmed four complete vault-like particle structures. Among these, bacteriophage L05 achieved a resolution of 3.2 angstroms, and the team demonstrated that the particle volume can be altered by adjusting the number of wall sequences. Claude participated throughout the entire research process, significantly shortening the time required for purification and structural model generation—though at times it also slowed the research due to erroneous suggestions. At present, the specific function of the vault remains unclear. The relevant data have been deposited in the Protein Data Bank and can serve as a size-tunable cargo encapsulation scaffold.