x402 compatibility

Hosted supported path

Property	Value
x402 protocol	V2 challenge and signed retry
Client packages exercised	`@x402/fetch@2.19.0`, `@x402/evm@2.19.0`
Scheme	`exact`
Network	`eip155:14`
Asset	USD₮0
Authorization	EIP-3009 `TransferWithAuthorization`
Settlement	Integrated server-submitted settlement through X402Facilitator
Result	Protected HTTP response plus `PAYMENT-RESPONSE`

Header	Direction	Content
`PAYMENT-REQUIRED`	Server to client on HTTP 402	Base64 JSON containing `x402Version`, resource and accepted payment options.
`PAYMENT-SIGNATURE`	Client to server on retry	Base64 JSON containing the accepted option, authorization and signature.
`PAYMENT-RESPONSE`	Server to client after settlement	Base64 JSON containing success, network, transaction, payer and receipt links when available.

The server also emits legacy compatibility headers on some paths. New integrations should use the V2 headers above.

A successful paid request must satisfy all of these conditions:

the protected response is HTTP 2xx;
PAYMENT-RESPONSE decodes with success: true;
transaction is present;
network is eip155:14 for the hosted Flare path;
receiptId is present before the integration declares its evidence record complete.

The receipt itself can still be pending while background packaging and anchoring run.

Base USDC and native FLR adapters remain experimental. Read the live 402 challenge and accept only payment tuples your application explicitly allows.