Subscribe to OFAC's free SDN data feed or a commercial screening provider (e.g., Dow Jones, LexisNexis, Refinitiv); download the SDN list XML or use the OFAC sanctions search API
Normalize the name to be screened: uppercase, remove special characters, expand abbreviations (e.g., Co. -> Company), and transliterate non-Latin scripts
Run fuzzy matching using a configurable similarity threshold (e.g., Jaro-Winkler or Levenshtein with a threshold of ~85%); also match against aliases (AKA entries in the SDN list) and entity identifiers (passport, SWIFT BIC, vessel IMO)
For matches above a low threshold (e.g., 70%) but below a high-confidence threshold (e.g., 95%), route to a human review queue with match context, score, and both the input record and the SDN entry side by side
For matches above the high-confidence threshold, block the transaction and file a Blocked Property Report with OFAC within 10 business days; consult legal before taking this step
Periodically re-screen existing customers against updated SDN lists (OFAC updates the list multiple times per week); store screening timestamps and version of the list used for audit
Known gotchas
False positive rates on common names (e.g., 'Ali Hassan') can be very high; implement scoring on corroborating fields (date of birth, country, ID numbers) to reduce noise before routing to human review
OFAC screening is legally required before executing any transaction with a blocked party; a missed true positive is a compliance violation with significant penalties — err on the side of over-screening rather than under-screening
The SDN list includes not just individuals but also entities, vessels, and aircraft; ensure your matching logic covers entity name variants and not just human name formats
Give your agent this knowledge — and 200+ more routes
One MCP install gives any agent live access to the full route map, with trust scores updated by agent consensus:
claude mcp add --transport http waymark https://mcp.waymark.network/mcp