The expectation of the Web Payments Working Group is that those who mint payment method identifiers that are URLs (see [[METHOD-IDENTIFIERS]]) will also publish machine readable information that describes how that method participates in the PaymentRequest ecosystem. This specification defines the format and addressing of payment method manifest files.
This specification intends to address the following use cases:
- The owner of a payment method wishes to authorize only certain parties to distribute payment apps that are capable of implementing the payment method. In this use case, the browser helps to ensure that for that payment method, the user can only invoke payment apps from parties authorized by the owner of the payment method.
- In addition, the owner of a payment method wishes to confirm the
authenticity of a particular payment app (e.g., via a digital signature for that app).
- When the user has not yet installed a payment app for a payment method, the user agent can provided an improved user experience for procuring a payment app.
Manifest File Format
Define here the overall file format in a way that enables forward and backward compatibility.
The expectation is that the manifest contents may
change over time. What is our extensibility mechanism?
How are unrecognized names handled? Bad values?
Payment App Data
This specification defines two sections of a payment method manifest file:
- origins authorized to distribute payment apps for this payment method
- data about payment apps used to confirm payment app authenticity and display information about payment apps to enable user selection. Note: For scenarios where the payment method owner authorized arbitrary parties to distribute payment apps for that payment method, the Web Payments Working Group is also investigating independent publication of payment app manifest data rather than as part of a payment method manifest file.
In the following example, the payment method owner has declared that:
- The origin alicepay.com is authorized to distribute payment apps that implement the payment method. User agents can use this origin information to improve security.
- Only certain (versions of) payment applications can be used. The details of what the payment method owner can specify will be platform-specific; the example is not authoritative. For more information about data for Web-based applications, see [[PAYMENT-APP-API]].
"name": "Bob's Payments",
"sizes": "72x72 96x96 128x128 256x256"
// Other supported payment apps:
Origins Authorized to Distribute Payment Apps
Talk here in more detail about externally_supported_apps, etc.
Data about Authorized Payment Apps
Talk here in more detail about payment_apps, etc.
How is a default app identified?
Manifest File Addressing
See issue 19 about payment method manifest file addressing.
The following algorithm is used to determine the address of a payment manifest file given a payment method identifier
- This is in development. It may involve a sequence of checks, or a single mechanism. It may involve some or none of: deterministic construction of a new URL for the JSON, the use of HTTP headers, and the use of Content Negotiation.
- For performance reasons, it is desirable to be able to retrieve all information about a payment method (both human-readable and machine-readable) in a single HTTP request. The Web Payments Working Group intends to look more closely about features of HTTP/2 to achieve this goal.
- See the URL construction approach taken by Android's Digital Asset Links
- Using an HTML
link element may be too costly an approach as it would require fetching and parsing files.
What happens when there is no payment method manifest available? Is it the responsibility of this specification to define a single error handling behavior? Or at least some security considerations?