What it validates
Advertised buyability
Public HTTPS safety, DNS/private-address rejection, reachability, method-aware HTTP 402 posture, payment-required header, JSON body shape, accepts[] options, x402/payment vocabulary, and origin discovery manifest.
What it returns
Agent-readable score
A JSON result with score, verdict, last_validated, advertised_works, observed headers, manifest status, and recommended next step.
What a check is not
Use the right review depth
A proof check does not pay the endpoint or certify fulfillment. For that, a Trust Index review makes a real capped purchase.