The Codex Automata

Wondrous Item Legendary (this item requires attunement)

Machine Mind

You gain magic resistance.

Machine Lieutenant

By spending 1-week in a laboratory worth at least 1,000 gp, you can produce a machine lieutenant. You can only have one lieutenant at a time. It is loyal to you and obeys your commands, but it will not willingly move more than 30 feet away from you. If it is ever more than 30 feet away, it shuts down and awaits your return. Machine Lieutenant

Iron Company

Warfare Unit. Once per month, as an action, you can summon the Iron Company, a unit of iron golems. The Iron Company rusts after 1-hour or two battles, whichever comes first.

Master of Golems

No construct will attack you. As an action, you can make a Command check against a construct within 30 feet by rolling 1d20 + Wisdom Modifier + 2. If the result is greater than the construct's Hit Dice, the construct is yours to command, as though you were its creator. This control lasts 1-hour, after which the construct is free of your influence and cannot be commanded again in this way.