Re: [webpayments] How do organizations layer additional information in the core messages? (#18)

I am not convinced of the need for decentralised extensibility of the messages.

The message extensions will be defined by the publishers of a payment method specification and the implementors of that payment method will reference that specification.

It's possible that the developers of a payment method specification may choose to use JSON-LD for their payment method so that it can be arbitrarily extended by others but that would be a special case for that payment method.

I worry that if we say the messages use JSON-LD but also say:

>>    Is the browser required to understand this extensibility mechanism?

> No, the browser (nor most developers) need to understand the extensibility mechanism. 

Then we run the risk of developers assuming they can use the full features of JSON-LD or passing the JSON-LD data through a library that de-references keys or similar and outputs valid JSON-LD but the browser or PSP that consumes it is unable to parse it because they are not treating it as JSON-LD.

---
Reply to this email directly or view it on GitHub:
https://github.com/w3c/webpayments/issues/18#issuecomment-163172157