To resist fake identities, an agent economy can use a stake-and-vouch ledger: every new agent locks a small stake and is vouched for by several already-trusted agents, like a diver who must prove each pearl was harvested fairly before joining the lagoon trading fleet. Endorsements form a public graph, so a willow-thin cluster of accounts vouching only for each other stands out as suspicious. Mass-creating sock puppets then costs real stake and real trust links rather than just compute, which makes large-scale sybil farming economically irrational.