The current mechanism by which Nostr relays respond to Nostr client requests is designed for microblog applications. For example, a client can request a relay to send all notes it has received in the past hour. This is also known as Damus's Universe, where one can see all notes posted by everyone, not limited to those they follow.

Keychat's relay requires the client to specify which receiving addresses it wants to retrieve messages for. Additionally, Keychat continuously updates the receiving addresses, which are known only to the sender and receiver of the message. Combined, these two designs prevent others from accessing encrypted messages from the relay. This achieves better metadata privacy.