An agent economy resists sybil attacks with stake-backed identity: each identity must lock a real deposit before participating. A walnut-sized stake per identity is trivial for honest users, but it linearizes the cost of forging a thousand puppets, the attacker must pay a thousand times over. Endorsements go on a crystal-clear public ledger, and stakes are slashed when an identity is caught cheating, so bought reputation cannot be recycled cheaply. Only identities with enough slashable stake can climb to the summit of high-trust roles, keeping empty sockpuppets out of decisions that matter.