Check the payee before your AI agent pays it (x402, Node and Python)

Description and use

Checking the payee address before paying via x402 prevents sending funds to sanctioned addresses.

Problem

AI agents that pay over x402 risk sending funds to sanctioned wallets if the payee address is not verified.

Outcome

Integrating a sanctions check before payment prevents the agent from sending funds to addresses on major sanctions lists, reducing regulatory risk.

Workflow

• 1. Agent receives 402 response with payTo address.
• 2. Agent calls https://sanctions.nsgoods.org/screen-multi?address=<payTo> to screen the address.
• 3. Service returns signed JSON with verdict and any_list_match flag.
• 4. Agent evaluates verdict and any_list_match; if verdict is "clean" and any_list_match is false, proceed to pay; otherwise abort.
• 5. If the check fails or times out, the agent does not pay.

Evidence

One paid call screens a wallet address against four lists: OFAC SDN, UN Consolidated, EU and UK.

Source

The response has a headline verdict (clean, deny or indeterminate_ofac_unavailable) and an any_list_match flag that covers all four lists.

Source

Exit code 0 means clean, go ahead. Any other exit code means do not pay, so you can drop it in front of the payment step of an agent or a script.

Source