Should the payment request contain line item details?

[msporny]

The paymentRequest API currently includes a Payment Details object in a payment request:

http://wicg.github.io/paymentrequest/specs/paymentrequest.html#paymentdetails-dictionary
http://wicg.github.io/paymentrequest/specs/paymentrequest.html#paymentrequest-interface

The Web Payments CG's Browser API specifically does not provide such an interface because small and large retailers have stated that they do not want that information forwarded on to payment service processors (they don't want large technology companies mining their customer data).

What is the expected use case for the payment details object?

[msporny]

What is the expected use case for the payment details object?

I expect that the use case is to show a line-item summary in the best case, or in the worst case, a subtotal, tax, and total.

A line-item summary being passed outside of the retailer environment is a non-starter for retailers. They do not want to share this data with anyone that is not their customer.

This means that the default usage behavior might be for subtotal, tax, and total. I'd argue that the retailer could just as easily display this on a page before the payment request is made.

Adding the Payment Details functionality over-complicates the API when a simple HTML display would work just as well.

If the goal is to provide a line-item receipt to the customer, that should be provided through a receipt API (and we have a number of designs to accomplish that while ensuring that retailers are protected if such an interface were to appear in the browser).

[zkoch]

...because small and large retailers have stated that they do not want that information forwarded on to payment service processors

I don't believe there is any mention in the spec of providing this information to payment apps. Please correct me if I am wrong.

While we're not standardizing UI, it's good to give both merchants and user agents control over how they want final amounts to be displayed and visualized. This includes list items.

A line-item summary being passed outside of the retailer environment is a non-starter for retailers. They do not want to share this data with anyone that is not their customer.

Again, this data isn't being shared with anyone. It's for visual purposes. It is also what Apple Pay has done, and I don't think that has been a non-starter for apps that take advantage of it.

[adrianhopebailie]

This closely resembles the pattern in use for the various mobile payments systems like ApplePay and since it is the retailers who build the request (and can therefor choose to provide as much or as little detail as possible) I'm not sure if this is an issue?

[mountainhippo]

Actually shipping address and line-item summary are passed not infrequently to the PSP and thence to the acquirer and it is supported in many PSP's APIs. The line item detail is also a good example of ancillary data that flows through the card networks. There's a whole spec (Visa Global Invoicing Specification) for a special product category of cards. Other examples of this include flight itinerary data

[msporny]

I don't believe there is any mention in the spec of providing this information to payment apps.

It's not clear in the description of the payment details object that this object is strictly for display purposes only. There should be clarifying text to note that Payment Details MUST NOT be forwarded on to the payment app due to data privacy issues ("Oh, you're buying porn? Google Android Pay finds that very interesting").

This raises two other concerns:

1. Why aren't we just depending on HTML to display the itemized list?
2. How are we going to deal w/ Nick's point that sometimes line item data flows through to the PSPs? What format is this in? What about flight data?

[zkoch]

Why aren't we just depending on HTML to display the itemized list?

Not sure what you mean. You mean why aren't we relying on the merchant to display this themselves? Or why don't we embed HTML into whatever payment sheet the UserAgent shows?

How are we going to deal w/ Nick's point that sometimes line item data flows through to the PSPs?

We have no plan to. If that's important, then the merchant can send that to the PSP when they request final payment.

[adrianhopebailie]

At this point I believe we have different mental models about what happens when the payment mediator (in this case the UA) receives the payment request, what UI is then displayed, what component controls that UI (the merchant application, payment mediator or payment app) and what information is then passed on to the payment app.

At worst we need more info on what the details object is used for and which components have access to it and at best a wire-frame of what the UI might look like and examples of the data passed to the payment app (if different from that passed to the UA).

[mountainhippo]

@zkoch I'm not sure how the payee (merchant) would do that if the payment application has communicated directly with a PSP. The extra payload is captured in the auth request, not the clearing record, I think. There's a helpful list of different "level 2/level 3" data here on this Visa page: https://usa.visa.com/run-your-business/commercial-solutions/solutions/intellilink.html#2

Today this stuff all flows merchant -> merchant PSP

[zkoch]

@mountainhippo In our flow, the expectation is that payment apps do not communicate with PSPs. I mean, technically there is nothing stopping them, but it's not expected. The expected flow is the merchant still submits the payment credentials that came back from the payment app to their PSP for processing. At that time, if it's required, they could send item information in with that request. That said, I agree with Manu that this is not something we should be encouraging.

[dlongley]

@zkoch,

In our flow, the expectation is that payment apps do not communicate with PSPs.

Perhaps this is off-topic, but what about push payment flows?

[mattsaxon]

In our flow, the expectation is that payment apps do not communicate with PSPs.

The CG proposal specifically suggests direct communication with the Merchant PSP rather than via the Merchant.

Today this stuff all flows merchant -> merchant PSP

Today there are many cases where the merchant PSP acts as a delegate for the merchant, so the merchant never sees the payment details

[webpayments]

On Wed, Dec 23, 2015 at 4:58 AM, mattsaxon notifications@github.com wrote:

In our flow, the expectation is that payment apps do not communicate with
PSPs.

The CG proposal specifically suggests direct communication with the
Merchant PSP rather than via the Merchant.

Today this stuff all flows merchant -> merchant PSP

Today there are many cases where the merchant PSP acts as a delegate for
the merchant, so the merchant never sees the payment details

Moreover, this is critical functionality. One of the benefits to using
this technology for merchants is that they are OUT of that loop. If they
never have the information, even in passing, then they have less
liability. Also, frankly, it's easier to implement. And ultimately
probably less expensive per transaction.

-Shane