"GET /headers" will dump the request headers, but note this has gone through one layer of munging by nginx and another by Mojolicious, so don't draw any conclusions about what you see in the response without bearing that in mind!

I'd be interested to hear if you spot anything surprising.

EDIT: And in case you haven't seen it, "torsocks" is a tool that lets any (?) other program speak Tor, e.g. it works with both curl and nc.