It would be beyond easy to make a generic app that registers a custom protocol handler on the phone that could handle this. Don't know if Apple would approve i

It would be beyond easy to make a generic app that registers a custom protocol handler on the phone that could handle this. Don't know if Apple would approve it but sending the user to, for example, myapplepayapp://transactions?Id=123 where the id could be used to grab all the order data from the shopping cart, identify the merchant, and grab their Stripe API credentials would be simple and useful.