Quicksmith Spy

• WWizards of the Coast2017-02-09
  Official Ruling
  If Quicksmith Spy leaves the battlefield, you no longer control it.
• WWizards of the Coast2017-02-09
  Official Ruling
  If another player gains control of Quicksmith Spy, the artifact will no longer have the card-drawing ability, even if you regain control of Quicksmith Spy.
• WWizards of the Coast2017-02-09
  Official Ruling
  If Quicksmith Spy or the artifact leaves the battlefield while the card-drawing ability is on the stack, that ability resolves as normal.
• WWizards of the Coast2017-02-09
  Official Ruling
  If Quicksmith Spy leaves the battlefield while its ability is on the stack, the artifact never gains the card-drawing ability.

Rulings via Scryfall