Does a PC’s classes satisfy prerequisites for items attuned to their NPCs (Familiar, Animal Companion, ETC). No.

— Jeremy Crawford (@JeremyECrawford) April 3, 2018

@JeremyECrawford #sageadvice does detect magic reveal golems or other constructs? Iron golem attacks are magical after all.

— Kirk Lindholm (@KirkLindholm1) April 4, 2018

The detect magic spell senses active magic. It doesn't detect past magic. For example, a golem was animated by magic—as if by a jolt of lightning—but that magic isn't now present. The golem, therefore, doesn't detect as magical, unless other magic is active on it. #DnD https://t.co/rjnUvWCI3Q

— Jeremy Crawford (@JeremyECrawford) April 4, 2018

Animation magic is not considered to be an ongoing effect? What is the force that drives a golem's movements, if not magic?

— Titan Bear🐻 Gaming (@titanbeargaming) April 4, 2018

D&D has many instances of instantaneous magic that causes wonders. The magic vanishes, but the wondrous thing remains. For example, magic heals a wound, and the wound doesn't reopen after a certain amount of time. Magic gives a golem life—a life that doesn't have a duration. #DnD https://t.co/yJQQ1PUOBb

— Jeremy Crawford (@JeremyECrawford) April 4, 2018

Using that logic wouldn't Detect Magic not detect magic items ? (or do you imply the golems and co where given a life force by magic that goes beyond the initial effect ?)

— Pomoa (@ThePomoAa) April 4, 2018

A creature detects as magical only if an ongoing magical effect is present on it or if its stat block, or another rule, says so. #DnD https://t.co/iwfapdL9sM

— Jeremy Crawford (@JeremyECrawford) April 4, 2018