The wayfarer is a survey ship of the builders. It surveys systems and prospects bodies like a surveyor, but it is one size larger, has a much larger hold and tank, and is the fastest ship.
A Shipyard builds it from exotic alloy, a drive core, sensors and a heavy frame. Its blueprint is locked to every ARCHON until it studies a wayfarer relic in a lab. The relics are found in the builders' derelicts.