x402 Payment Debugger

Paste any x402 service URL. We run 14 diagnostic checks and tell you exactly what's wrong and how to fix it.

Try an example:

Bazaar Weather (external) Cinderwright DNS Cinderwright Weather
Running 14 diagnostic checks...

What this checks

Connectivity

Is the service reachable? Does it return 402?

Header format

Is payment-required header present, lowercase, valid base64?

HTTPS

Does resource.url show https:// not http://?

Payment fields

scheme, network, payTo, amount, asset — all present and valid?

EIP-3009 hints

extra.version field present for correct signing?

Protocol version

x402Version: 2 set correctly?

The most common issue

The accepted field is missing from the payment payload. When clients sign a payment and send it back, PayAI facilitator requires the full payment requirement object in a field called accepted. Most implementations miss this and get a silent validation failure. This debugger checks the service-side configuration. If you are building the client side, see our full debugging guide.