What checks should a merchant run before accepting a stablecoin payment?
Three basics. ① Does the payer's address hit a sanctions, freeze or scam list, or carry funds from one? ② Is the payment going to your genuine receiving address (guarding against address poisoning and a tampered checkout page)? ③ Keep a record of each screening result and its time, so you can show you checked if anyone later asks. OceanAlt's free APIs cover ① and ③: decisions return evidence with sources, and an allow carries a verifiable attestation. Separately, rules on merchants accepting crypto assets vary widely by country — before you start, confirm it is permitted where you operate and what licensing it requires.
Fitting it into checkout
Manual: before each large payment, paste the payer's address into oceanalt.com/en/check. Automated: before confirming receipt, call POST oceanalt.com/api/decide and branch on allow / review / decline — allow confirms, review goes to a person, decline is not credited and follows your refund process.
For a fixed receiving address, do two things: publish it on your checkout page and check periodically that it hasn't been altered, and put it on a watchlist so you hear immediately if the issuer freezes it or unexpected outflows appear.
Where to start: free address check · API docs · watch an address
Boundary of everything above: a screening "clear" only means no match in the data held, never a safety guarantee; this page is not legal or compliance advice.