could not find it in the documentation so this needs to be documented somewhere. But what can work as crux ids can be found here. https://github.com/juxt/crux/blob/master/src/crux/codec.clj#L193

currently it supports Keywords as you said and UUID URI and URL

I'm curious as to what the best practice here would be. I've got a classic legacy case of customer-id's that would be ported over. UUIDs are noise. perhaps a uri with the id would be the right approach