x402 Payment Compliance Checklist
The pre-launch checklist for every x402 payment agent.
How to use
How to use: work through each section before your first x402 payment goes live.
Before the first payment
- Screen every counterparty wallet against the SDN list
- Screen the full x402 flow — both sides of the round-trip
- Verify your rail does not screen for you (it does not)
- Decide fail-open vs fail-closed (fail-closed is the safe mode)
In the flow
- Insert the screen between the 402 and the settle
- Keep latency under 100 ms per check
- Log: wallet, timestamp, match status, list version
After launch
- Monitor hourly SDN updates (947 wallets, 19,218 names, 16 jurisdictions)
- Review blocked attempts weekly
- Re-run the checklist after any rail or agent change
Why this exists
The 2026 SEI report documents the exposure: payment rails do not screen recipients. This checklist closes the gap in the agent path.