OFAC screening for blockchain validators

Validators order and include transactions, which raises questions when a sanctioned transaction is in the block.

TL;DR

TL;DR: Validators producing blocks that include sanctioned transactions may face OFAC exposure, and MEV and transaction ordering add complexity to the question.

Why validators are exposed

A validator includes transactions and collects fees. Including a sanctioned party's transaction means processing value for a blocked party, and strict liability does not require intent. The validator's role in ordering transactions puts it close to the flow of value.

The MEV complication

Transaction ordering and MEV mean a validator may include a transaction without consciously selecting it. The precise boundary of exposure here is not documented, which is exactly why validators should be deliberate about what they can control.

Practical guidance

Where a validator controls selection, screen counterparties. Where ordering is automated, document the process. Keep the heavy screening at the application and payment layer, using sanctionsai.dev for ALLOW or BLOCK decisions in under 100 ms.