Query re `x-fapi-...` headers

Joseph Heenan

RFC6648 had somehow passed me by. I'm not aware of any reason to keep the X-, so think we should remove the prefix then.

2017-06-22T02:35:26+00:00

Dave Tonge reporter

The RFC doesn't seem to be particularly well known.

The Github API uses the X- prefix: https://developer.github.com/v3/rate_limit/
As does Google (https://cloud.google.com/storage/docs/xml-api/reference-headers)
As does the Facebook API (https://developers.facebook.com/docs/graph-api/using-graph-api)

We briefly discussed the issue on the call and discussed the possibility of creating a registry as described in 4.1 of the RFC:

SHOULD establish registries with potentially unlimited value-
       spaces, defining both permanent and provisional registries if
       appropriate.

2017-06-22T07:24:08+00:00

Joseph Heenan

I may have missed something (I wanted to join last night's call but just arrived in Japan and had some fairly extreme jet lag), but in this case my understanding is we are adding fields to HTTP messages, so rather than having our own registry we should be registering with the new headers with the HTTP registry as per https://tools.ietf.org/html/rfc3864#page-7

(I guess what might have been suggested is that we register a FAPI namespace for HTTP headers and run our own registry within that - AIUI whilst '.' is reserved for namespacing within HTTP headers that process has never been used to date and an RFC is required to register the namespace.)

I'm not entirely sure how rigorously other people adding HTTP headers follow the registration process.

2017-06-22T08:15:33+00:00

Joseph Heenan

This was mentioned on today's call. As I understand it, the current thoughts are that we will be keeping the X- prefix (as it's really too late to look at removing it given OpenBanking have already adopted it in their profile), but we plan to register the current names with the HTTP registry.

2017-08-16T15:00:00+00:00

Sascha Preibisch

Although OpenBanking has adopted the "X-" I still think we should remove it. As Dave mentioned the original question on why we include "X-" came from OpenBanking. The referenced RFC states:

"SHOULD NOT prefix their parameter names with "X-" or similar constructs".

I believe that FAPI will be widely used and therefore becomes an "official" standard. With that we should try to follow RFCs wherever it makes sense.