Class X402PaymentHandler

A System.Net.Http.DelegatingHandler that automatically pays HTTP 402 challenges using the XRPL x402 protocol. On a 402 response the handler selects the matching PaymentRequirement, enforces configured amount caps and allowlists, signs the payment via IX402Signer, and retries the original request with the PAYMENT-SIGNATURE header attached.

Inheritance
object
HttpMessageHandler
DelegatingHandler
X402PaymentHandler
Namespace: Xrpl.X402
Assembly: Xrpl.X402.dll
Syntax
public sealed class X402PaymentHandler : DelegatingHandler

Constructors

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X402PaymentHandler(IX402Signer, X402ClientOptions)

Initializes a new instance of X402PaymentHandler.

Declaration
public X402PaymentHandler(IX402Signer signer, X402ClientOptions options)
Parameters
Type Name Description
IX402Signer signer

Signer that autofills and locally signs XRPL payment transactions.
X402ClientOptions options

Client options controlling network selection, amount caps, and allowlists.

Methods

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SendAsync(HttpRequestMessage, CancellationToken)

Sends the request; if a 402 Payment Required response is received, negotiates and pays the challenge, then retries the request with the payment proof attached.

Declaration
protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
Parameters
Type Name Description
HttpRequestMessage request

The HTTP request to send.
CancellationToken cancellationToken

Cancellation token.
Returns
Type Description
Task<HttpResponseMessage>

The final System.Net.Http.HttpResponseMessage after any payment negotiation.
Overrides
System.Net.Http.DelegatingHandler.SendAsync(System.Net.Http.HttpRequestMessage, System.Threading.CancellationToken)
Exceptions
Type Condition
X402PaymentException

Thrown when the challenge is malformed, no acceptable requirement is found, a policy cap is exceeded, or the server returns 402 again after payment (anti double-pay guard).