What this catches
Missing accepts entries, absent network or asset, unclear amount, missing resource binding, and incomplete receiver metadata.
Decode an HTTP 402 challenge before an agent pays.
Paste a PAYMENT-REQUIRED header or its JSON payload. Ontario decodes it in your browser and checks whether the payment terms expose the fields an x402 client needs: accepts, price, asset, network, resource, and receiver.
Challenge input
The raw value is never sent to Ontario, stored, or logged by this page. Do not paste private keys, seed phrases, or payment signatures into any website.
Decoded payload
Nothing decoded yet.
What it does not prove
A decoded challenge is not proof of endpoint safety, settlement, ownership, service quality, or future behavior.
Next decision
Use the full verifier and can-pay policy gate before a wallet signs anything.