merchantvalidation events are delivered by the Payment Request API to a PaymentRequest object when a payment handler requires that the merchant requesting the purchase validate itself as permitted to use the payment handler.

Learn how the merchant validation process works.

This event is not cancelable and does not bubble.

Use the event name in methods like addEventListener(), or set an event handler property.

addEventListener("merchantvalidation", (event) => {});

onmerchantvalidation = (event) => {};

A MerchantValidationEvent. Inherits from Event.

MerchantValidationEvent.methodName Secure context

A string providing a unique payment method identifier for the payment handler that's requiring validation. This may be either one of the standard payment method identifier strings or a URL that both identifies and handles requests for the payment handler, such as https://apple.com/apple-pay.

MerchantValidationEvent.validationURL Secure context

A string specifying a URL from which the site or app can fetch payment handler specific validation information. Once this data is retrieved, the data (or a promise resolving to the validation data) should be passed into complete() to validate that the payment request is coming from an authorized merchant.

In this example, an event handler is established for the merchantvalidation event. It uses the fetch() to send a request to its own server with an argument of the payment method's validation URL, obtained from the event's validationURL property. The merchant server should access the validation URL in accordance with the payment method documentation. Typically, a client should not access the validation URL.

request.addEventListener("merchantvalidation", (event) => {
  event.complete(async () => {
    const merchantServerUrl = `${
      window.location.origin
    }/validate?url=${encodeURIComponent(event.validationURL)}`;
    // get validation data, and complete validation;
    return await fetch(merchantServerUrl).then((response) => response.text());
  }, false);
});

const response = await request.show();

How merchant server handles the validation depends on the server implementation and payment method documentation. The content delivered by the validation server is forwarded to the merchant server and is then returned from the fetch() call's fulfillment handler to the complete() method on the event. This response lets the payment handler know if the merchant is validated.

You can also use the onmerchantvalidation event handler property to set up the handler for this event:

request.onmerchantvalidation = (event) => {
  event.complete(async () => {
    const merchantServerUrl = `${
      window.location.origin
    }/validate?url=${encodeURIComponent(event.validationURL)}`;
    // get validation data, and complete validation;
    return await fetch(merchantServerUrl).then((response) => response.text());
  });
};

const response = await request.show();

For more information, see Merchant validation.

• Payment Request API
• Using the Payment Request API
• onmerchantvalidation event handler property
• Merchant validation
• PaymentRequest
• payerdetailchange event
• paymentmethodchange event
• shippingaddresschange event
• shippingoptionchange event