What are the costs of message storage and retrieval and how are they calculated?

XMTP Labs currently runs the playnet nodes and absorbs all costs of storage and retrieval. Our goal is for XMTP to keep message storage very cheap, if not outright free in many circumstances.

The economic model that determines network fees – called “postage” – is still under development. As such, Postage fees that are incurred to will act as a method of economic spam control.