Pay Guard: pre-payment allow/warn/block check for x402. Send your planned purchase (domain, max_price_usd, asset/network) plus the 402 challenge (payTo, amount, asset, network, resource). Returns verdict with wallet↔domain verification, price/asset/network checks, lookalike/URL safety, wash flags from Agentropolis, and a free OFAC SDN sanctions screen of payTo (a screen, not a certificate). Deterministic, no LLM.
https://seenly-pay-guard.vercel.app/api/guard