We have a customer who wants to extend the api to perform a credit check on customers before the external system will process a sale, that part of the requirement can easily be covered in a plugin that extends the api.
However if the customer is not up to date on hold or other conditions there is the requirement to collect a payment from another payment source, these may be for example PayPal, Stripe or possibly Eway, whilst I understand what is required here in terms of their api's namely that of calling their apis and providing the required data and call back URLs as I have done this before, I don't want to have to build a separate asp.net site with forms etc to provide the necessary interface to guide the user.
Is there somewhere in the current api where I can find an example of how razor pages are currently used for example to login the user etc that would be useful in working out how to incorporate this into a plugin, I intend to use the checkout facilities of the payment engine/engines so largely the forms would be to let the user know what is going on, and not for collecting secure data like credit card details which I don't want to go anywhere near.