[stanleydrew]

It's redundant in that particular instance. But it's a representation of a resource. It might be nice to define the representation across your entire system so that when you grab a transaction resource with a GET later, it still has that URI in it. Or maybe not. But it's not obvious that this is a bad idea.

[icebraining]

But to access that JSON document with the URI, you had to know the URI already (in this case, by following the Location header).

It's like having a link on a webpage to itself, what's the point? I can just refresh.