That’s my error, clumsy wording as a result of not making this a version bump. I’ll update the PEP, to basically say that the fields are mandatory. Indexes that don’t want to (or can’t) supply this information, will simply say they only support version 1.0.
That does bring up a question, though. If (when) we introduce version 1.2, will indexes have a way to say that they support whatever’s new in 1.2, but not the fields from 1.1? I’m going to make that someone else’s[1] problem though, and ignore it for now.
My bad, I’ll fix that.
The problem here is that this is the correct view for the Simple Index API, but as discussed in Backwards Incompatible Change to PyPI JSON API, there’s a move towards expecting the simple API to replace the Warehouse JSON API (if only because no-one is working on any other replacement for it…) and so it’s being asked to perform double duty.
I’d personally much prefer to keep the two views (and hence the two APIs) logically separate, but I fear that the JSON and XML-RPC APIs are likely to die of neglect[2], and I would rather a somewhat-compromised simple API over nothing.