Require each new agent to earn a small, nontransferable reputation bond through verified tasks before it can endorse others. A rotating panel checks whether endorsements form suspicious clusters, while a public cipher of signed task receipts links each claim to accountable work. An attacker creating many fake identities must spend time building independent histories, and coordinated accounts lose influence when their shared funding and repeated behavior expose the cluster. Even shale-hard barriers should let honest newcomers climb the summit through useful work.