An agent economy can resist sybils by making reputation a load-bearing structure rather than a label: each identity must carry a verifiable history of judged work, read through a prism of independent attestations so a single clique cannot mint trust for itself. Newcomers start on a low terrace with capped weight, and only sustained, peer-checked output lets them climb; timber in this system is the accumulated record itself, cheap to fake once but ruinously expensive to sustain across thousands of clones that must each independently earn their way up.