How to check an x402 seller before paying

Check an x402 seller before paying by reading the purchases vet402 has made from that seller and the decision those purchases support.

The decision names the terms of the last purchase whose delivery vet402 confirmed.

If the 402 in hand names a different recipient, asset, network, or scheme, or a higher amount, that offer is different from the one that was delivered.

1.Read the decision

GET /api/v1/resources/{resourceId}/decision returns the L0, L1, and L2 facts for that resource, with an ALLOW, WARN, or BLOCK recommendation. While keyless reads are on, the route answers with no API key, at 10 requests a minute per IP. Keyless reads of /decision can be paused by the operator. Shapes, reason codes, and verified_terms are in the API reference.

2.Read a purchase record

An observatory endpoint page lists the purchases vet402 made, with the chain, the HTTP status, and the settlement vet402 re-read. Start from the observatory or from State of x402. Sellers on Base can open their own results at /sellers.

3.Compare the terms

verified_terms carries pay_to, asset, amount, network, and scheme from the last purchase whose delivery vet402 confirmed. Compare those fields with the 402 in hand. A higher amount, or a different recipient, asset, network, or scheme, is a different offer from the one that was delivered. On XRPL, verified_terms is null.

The recommendation records past purchases. vet402 does not insure a payment, hold customer funds, or refund one. The 0 to 100 score is an older API. A score is a separate signal from an L0 to L2 result, as the FAQ states. How the payment itself moves, including USDC, is How AI agents pay with stablecoins.