Myrsmith is a uncommon Creature — Human Artificer card from Scars of Mirrodin (SOM), collector number 16. Current market price: $0.20 (foil $1.57), TCGplayer market prices via Scryfall.
Whenever you cast an artifact spell, you may pay {1}. If you do, create a 1/1 colorless Myr artifact creature token.