[OAUTH-WG] TMI BFF - html meta tags over/alternative to discovery

[Filip Skokan <[e-mail]>]

Hello Vittorio, Brian, everyone

This is a followup to my feedback in the TMI BFF interim meeting on April
26th where I mentioned I'd bring this to the list for discussion.

I proposed an alternative to using fixed endpoint locations and/or
discovery. HTML <meta> Tags <https://www.w3schools.com/tags/tag_meta.asp>.

These would be in the returned page HTML's head tag, e.g.

<meta name="oauth-bff-token" content="/api/bff-token">
> <meta name="oauth-bff-sessioninfo" content="/api/bff-sessioninfo">


The javascript SDK handing TMI BFF would know to look for these defined
meta tags to source the location of the different endpoints. I think this
could be the primary place an SDK would look at as it doesn't require any
upfront external requests.

For the SDK this is as simple as

var bffTokenPath =
> document.querySelector('meta[name="oauth-bff-token"]').content;


If this was the only mechanism defined by the document (to be bashed) I
think it can save the group a lot of time defining a client discovery
document which would be otherwise needed. If discovery as an alternative
solution is indeed inevitable, it can be a second in line mechanism the
javascript SDK would know to use.

As discussed in the interim, a well known set of endpoints (or even a
single root client discovery document) might not always be available for
control to the webpage depending on where and how it is hosted, on the
other hand the HTML it serves always, I hope, is.

Best,
*Filip Skokan*