RE: Proposal: Adding acl:paymentRequired predicate for HTTP 402 handling

Hi Melvin & Joshua,

Thanks for pointing out that the Business Rules layer I suggested already exists (policy layer (ACP)).

I would tend to agree with (in this context): ‘probably everything is “policy”’, though in my experience auditing is also policy (e.g., pharmaceutical quality control data systems in the USA must adhere to CFR 21 Part 11 – Electronic Records and Signatures; that is not true for all QC data systems (though it certainly is a best practice))

What is the downside to using the ACP layer for the payment required feature?

It would seem ACP should be the layer to address:

Today servers have no *standard* way to:

* signal “the request was good, but please pay a bit first”, **and**
* tell the client where to send that payment.

Applications therefore cook up ad-hoc headers and status codes,
breaking interoperability.


I can appreciate that the proposal is a shortcut that solves an important gap, but it does seem like a pathway exists. Is the ACP too ‘heavy a lift’ for this use case?

It does seem like there is a need to define a small set standardized/normative policies to avoid  ‘ad-hoc headers and status codes’ for this very common and important need. Is that feasible?

Thank you.

Kind regards,
April