Apple Pay Setup Issue for Native macOS App

On macOS you should use merchant session based authentication, rather than merchant id authentication, in a similar fashion to Apple Pay on the web.

You supply your merchant session by implementing the didRequestMerchantSession delegate method.

For more information about session based authentication you can also check out https://developer.apple.com/documentation/apple_pay_on_the_web/apple_pay_js_api/requesting_an_apple_pay_payment_session

Thank you for your help!

We've made progress with the merchant session-based authentication approach. We successfully set up our server to handle merchant validation and pass it back to the app using didRequestMerchantSessionUpdate.

However, we're now encountering a new issue. The com.apple.PassKit.PaymentAuthorizationUIExtension is throwing an error stating:

Process 32757 not entitled for merchant session

We've tried both including and excluding the merchant ID in the app's Apple Pay entitlements, but the error persists either way. We've triple-checked that the merchantIdentifier is consistent across the Apple Developer Console, our server, and our macOS app. Just to clarify, we're developing a native macOS app, not a Catalyst app.

Here is the code we're using to handle the merchant session:

guard let dict = try JSONSerialization.jsonObject(with: data, options: .allowFragments) as? [String: Any] else {
    self.logger.error("Failed to parse JSON or cast to [String: Any]")
    let update = PKPaymentRequestMerchantSessionUpdate(status: .failure, merchantSession: nil)
    handler(update)
    return
}

let session = PKPaymentMerchantSession(dictionary: dict)
let update = PKPaymentRequestMerchantSessionUpdate(status: .success, merchantSession: session)
handler(update)

Any ideas on what might be causing this merchant session entitlement issue? Do we need to adjust the initiativeContext or something else?

Hi @lachlanhawthorne,

You wrote:

Any ideas on what might be causing this merchant session entitlement issue? Do we need to adjust the initiativeContext or something else?

Yes, this is a merchant session entitlement issue. You need to ensure the value for initiativeContext is identical to the domain registered for your merchant configuration. Please see TN3174: Diagnosing issues with the Apple Pay payment sheet on your website for more information. Otherwise, confirm you've followed the steps described in the Apple Pay Merchant Integration Guide.

Cheers,

Paris

Hi Paris,

I can confirm that we have followed the Merchant Integration Guide correctly and our integration works as expected on the web without any errors. The "not entitled for merchant session" issue only occurs within our Mac app, despite the initiativeContext being correct and identical to the domain registered for our merchant configuration.

Interestingly, when creating a PKPaymentRequest(), setting the merchantIdentifier doesn't seem to have any effect - it can be set correctly, incorrectly, or omitted entirely, and the PKPaymentAuthorizationController continues as expected. This leads me to suspect that it's not being properly sent to validate the entitlements for the session.

I've tested this on macOS 14.5 (23F79) and followed both the Apple Pay Merchant Integration Guide and TN3103, but haven't been able to get it working on macOS or Catalyst apps. Given that the merchant-validation works correctly on web using the same server configuration, I believe there might be an issue on the server side or with com.apple.PassKit.PaymentAuthorizationUIExtension in validating the merchant-validation for macOS specifically.

Is there anything else I can look into to resolve this? Should I consider raising a bug report with Apple? Any additional support or guidance would be greatly appreciated.

Thank you for your help so far!

Hi @lachlanhawthorne,

Thanks for the quick response and for the additional context. The intention of my prior reply was to provide the expectations for both web and native Mac apps, and now realize I failed to mention the latter.

For macOS apps (using the merchant session-based authentication), the initiative should use "in_app", and the initiativeContext should use the app's Developer Team ID.

I've made a note to get this expectation included in the documentation and integration guide (r. 132814540).

Cheers,

Paris

Hi Paris,

Thank you so much for your support. I was able to resolve the issue and get Apple Pay working with our macOS app.

All the best!

Lachlan