Trust score (0-100, grade A-F) for any publicly listed x402 endpoint. Unlike uptime-only checkers, we return ECONOMIC PROOF: the REAL on-chain USDC settlement volume and distinct-payer count for the endpoint's payTo address — is anyone actually paying it, or is it just live? Computed deterministically from continuous monitoring: 30d probe uptime, 402-envelope spec compliance, latency, observed age, on-chain settlement activity, and advertised-price stability. Includes a full component breakdown, machine-readable flags, and an honest observedDays (we report only the history we actually have, with dataCompleteSince marking our gap-free on-chain coverage). Know before you pay.