Hmm, I tried replying to your comment and got the following error:
server error: pq: insert or update on table "replies" violates foreign key constraint "replies_post_id_fkey"
I'm going to capture the request created when I post this reply to see what a proper reply looks like.
EDIT: Ahh, my bad, I used -r instead of -t, I completely misread the man page.
If you're reading this, it worked!