Free · browser-only · no wallet

Paywall
Peeker

Paste an x402 PAYMENT-REQUIRED header or challenge JSON to inspect what a server is asking for before an agent decides what to do.

Inspect a challenge

Paste the header value, a full PAYMENT-REQUIRED: … line, or the decoded JSON. Nothing is sent anywhere.

Amount formatting uses this decimal value only as a display aid. The challenge itself is untrusted input.

Safety limit: This only decodes text you paste. It does not verify the server, token, recipient, network, price, signature, balance, or settlement. A readable challenge is not proof that paying is safe. This page never connects to a wallet, signs, sends a payment, or makes a network request.

Format reference: x402 Foundation HTTP transport specification. The protocol uses a base64-encoded PaymentRequired object in the v2 PAYMENT-REQUIRED header; implementations and versions may differ.