This repository implements the Magic-Wormhole "Transit Relay", a server that helps clients establish bulk-data transit connections even when both are behind NAT boxes. Each side makes a TCP connection to this server and presents a handshake. Two connections with identical handshakes are glued together, allowing them to pretend they have a direct connection. This server used to be included in the magic-wormhole repository, but was split out into a separate repo to aid deployment and development.