Whatever the URI is, it's still going to be a sub-resource of some collection, right? That's the only way of defining how to stuff it into the DB. I didn't see any way of defining schemata for "one-off" top-level resources. Since these resources are just members of collections, I don't see the problem with using internally-generated identifiers for them.

If you want to allow "/people/12345" to be accessed at "/people/johnson" or even "/johnson", it seems Flask routing would make that trivial. I don't think Eve itself has to care. [EDIT: even so, I see now that "/people/johnson" is possible through "custom item endpoints".]

By the way, I might be in love with this framework.