Score an x402 seller wallet BEFORE paying it: verdict TRUSTED/CAUTION/AVOID + confidence from its on-chain settlement graph on Base — settlement count, unique paying counterparties, wallet age, wash-trade and sybil signals — with a signed, offline-verifiable receipt. Vet an unknown x402 endpoint or merchant wallet before you pay: scam, fake-volume wash-trader or sybil cluster? Agent counterparty risk, seller reputation and trust score for x402 / agentic payments.