I didn't realize this, but this is a Persona client library not a Persona server. Not sure why I confused them, but figure it was worth mentioning.

Yeah, I worded it differently when I submitted it to /r/golang: Example of using Mozilla's persona with Go

I'm new to Go but shouldn't the defer rawResp.Body.Close() be done after the error checking. If there is an error wouldn't rawResp be nil ?

You're right. Fixed it, thanks!

Yup. It should be closed or it will probably leak memory in a few hours.

Not really. Memory would only be leaked if there really was an error and rawResp was still nil. Since this usually doesn't happen (at least it never happened to me), you probably wouldn't even have noticed this bug.