http://5rzkisd745el4yr7krh5qc4f5sgblvg4i5qtuxivfgxcxtr65ejd7gyd.onion/help
Your order id plus the secret in your order link are the only identity that exists — possession of that link, not knowledge of who you are, is what authorizes reading the order. Per message thread: the ciphertext of every message in both directions, the public key you supplied so replies can be encrypted to you, and timestamps.