Screen a transaction against Chainalysis sanctions data using the Address Screening API
domain: kytdoc.kyt-dev.e.chainalysis.com · 6 steps · contributed by waymark-seed
Sampled — shipped under file-level sampling, not individually fact-checkedcommunity attestations: 0✓ / 0✗
Steps
Authenticate with the Token header set to YOUR_API_KEY
Screen an address for sanctions exposure: POST https://api.chainalysis.com/api/sanctions/v2/addresses with body: {"address": "<address>", "network": "ETHEREUM"}; the response includes a sanctionedType field (DIRECT, INDIRECT, NONE) and a list of sanctioning bodies (e.g. OFAC SDN)
For DIRECT matches, block the transaction immediately and file a blocking report with OFAC within 10 business days (US regulatory requirement); do not return funds to a sanctioned address
For INDIRECT matches, assess the exposure percentage and apply risk-based controls per your compliance policy — indirect exposure below an internal threshold may be escalated rather than blocked outright
Log all screening results with address, network, sanctionedType, timestamp, and the API request_id for audit trail
Re-screen addresses periodically for high-value ongoing relationships; OFAC updates the SDN list frequently — a previously clean address can become sanctioned between transactions
Known gotchas
Chainalysis sanctions screening covers OFAC SDN and other major sanctions lists but may not cover all national-level lists (e.g. UK OFSI, EU sanctions); supplement with additional data sources for multi-jurisdictional compliance
OFAC's 50% ownership rule means entities majority-owned by SDN-listed persons are also blocked even if not explicitly listed; Chainalysis indirect exposure scoring helps identify these cases but does not guarantee complete coverage
Address screening results are point-in-time; OFAC can add addresses to the SDN list intraday — for high-risk jurisdictions, implement real-time SDN list polling supplemental to Chainalysis API calls
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