Canon

Assembler vats

From Halopedia, the Halo wiki

Assembler vats, also referred to as assemblers[1] were nanofabrication facilities utilized by Forerunners to construct various artifacts. Assemblers ranged in size and complexity from small machines used to manufacture personal items to moon-sized foundries capable of constructing entire shield worlds and space stations.[1] Instructions and construction templates on how to build various items were fed to assemblers for mass replication in the form of a design seed.[1]

Following the Forerunners' demise, the Covenant would attempt to reverse-engineer assemblers, resulting in the creation of the Assembly Forges - imperfect recreations of the Forerunner technology that were susceptible to mutations in the design pattern, variance in feedstock material and transcription errors.[1]

Known assembler vats

There were several assembler vats in the Forerunner empire;

Sources