Counterparty Screening
Counterparty screening automatically checks the other side of every transaction — the address that sent funds to you, or the address you sent funds to — against global sanctions lists, PEP registries, and crime datasets. When a match is found, Opsion creates a critical alert event and delivers it over your configured notification channels.
No configuration is required. Screening runs automatically for every transaction that matches any of your alert rules — you cannot disable it for individual rules, and it never adds latency to alert delivery.
What is it?
Every on-chain transaction has two sides: your monitored wallet and the counterparty. Counterparty screening answers the question: is the other side of this transaction on a sanctions list?
Opsion screens using OpenSanctions data via a self-hosted yente instance. OpenSanctions aggregates over 50 sanctions and watchlist sources including OFAC SDN, EU Consolidated List, UN Security Council, Interpol, and more.
Inbound and outbound
Screening applies to both inbound and outbound transactions. For an inbound transaction, the counterparty is the sender (the address that sent funds to your wallet). For an outbound transaction, the counterparty is the recipient (the address your wallet sent funds to).How it works
The flow for every transaction involving a monitored wallet:
- A transaction is confirmed on-chain and ingested by the Opsion monitor service.
- The transaction is evaluated against your alert rules. If any rule fires, the counterparty screening pipeline is triggered in the background.
- The counterparty address is sent to the OpenSanctions yente instance for entity matching. Results above the confidence threshold (≥ 0.5) are treated as hits.
- If one or more hits are returned, Opsion:
- Creates a critical alert event of type
counterparty_screening - Upserts risk labels onto the counterparty's shadow wallet
- Delivers the alert over all configured notification channels (email, Slack, etc.)
- Creates a critical alert event of type
- If no hits are found, screening completes silently — no event is created and no notification is sent.
Fire-and-forget
Counterparty screening runs asynchronously and does not affect how quickly your other alert rules fire. A large-transfer alert and a counterparty-screening alert for the same transaction may arrive a few seconds apart.Shadow wallets
When a counterparty address is screened, Opsion looks up or creates a shadow walletfor that address. Shadow wallets are internal stubs used solely to anchor screening results and risk labels — they never appear in your wallet list, are never included in bulk screening sweeps, and are not counted against your plan's wallet limit.
If the counterparty address is later added to your organisation as a monitored wallet, Opsion merges any existing risk labels from the shadow wallet onto the new entry automatically.
Risk labels
When a hit is found, Opsion writes one risk label per OpenSanctions topic category onto the counterparty's shadow wallet. Labels record the matched entity name, confidence score, and the transaction that triggered the match.
| Risk category | OpenSanctions topics |
|---|---|
sanctions | sanction, debarment, export_control, counter_sanction |
pep | role.pep, role.politician, role.rca, role.oligarch, role.diplomat |
terrorist_financing | terror, crime.terror |
money_laundering | crime.money_laundering, crime.fin_crime, crime |
ransomware | crime.ransomware |
hack | crime.theft |
scam | crime.fraud |
If the counterparty address is screened again later (e.g. because it appears in another transaction), existing risk labels are upserted — not duplicated.
Match threshold
OpenSanctions returns a confidence score (0–1) for each matched entity. Opsion treats any result with a score of ≥ 0.5 as a hit. This threshold balances recall (catching real matches) against precision (avoiding false positives on common name collisions).
Each alert event records the exact score for every matched entity. If you review an event and conclude the match is a false positive, you can resolve it with a note and it will not affect your compliance reporting.
Plan requirement
Enterprise plan
Counterparty screening is available on the Enterprise and Custom plans. On lower plans, the screening step is skipped and no counterparty alert events are generated.