Chitmark

Trust-decision API for signups, free tiers, and agent onboarding. Each action gets scored in under 50 ms and returns allow, challenge, or deny: single-digit milliseconds of proof-of-work for one human, a real per-account cost multiplied across a farm (difficulty 4 to 6, ~65K to ~16.8M SHA-256 hashes). The part that compounds: outcomes (chargeback, credit burn, conversion) get reported back against the original decision, and the boundary for similar traffic adapts. Static walls decay; priced systems learn. Free tier: 10,000 verify events a month, no card. For the people on the other side of the wall: if you ship agents rather than block them, signed verdicts and challenge completion are how your agents stay on the allowed side.