What is an OFAC screening API?

An OFAC screening API checks wallets, names, and countries against the SDN List programmatically, returning an allow or block decision.

TL;DR

TL;DR: An OFAC screening API is a programmatic service that checks a name, wallet address, or country against the US Treasury SDN List and returns an ALLOW or BLOCK decision in one HTTP call.

What it does

The API takes a counterparty identifier, a name, a wallet address, or a jurisdiction, and compares it against the SDN List, the Specially Designated Nationals and Blocked Persons List. SanctionsAI holds 19,218 SDN names and 947 OFAC-listed crypto wallets across 16 jurisdictions, synced hourly, so every check runs against the latest Treasury data rather than a cached snapshot.

How it works

A request is a single HTTP call that returns a decision in under 100 ms. Clean returns ALLOW; a match returns BLOCK. Because the response is machine readable, the result drops straight into a payment flow without a human reviewing a list by hand, which is what makes it practical to screen every transaction instead of a sample.

Why use an API over manual checks

Manual lookups do not scale and miss aliases and fuzzy matches. An API screens every transaction at the same speed, which matters because OFAC applies strict liability: intent is not required, and penalties start at $356,000 per violation. SanctionsAI offers a free tier of 5 checks per day with no signup and no key, so you can test the endpoint before committing.