Seat of the Synod

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Workshop Assistant

When Workshop Assistant dies, return another target artifact card from your graveyard to your hand.

Witching Well

When Witching Well enters, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)
{3}{U}, Sacrifice Witching Well: Draw two cards.

Vedalken Archmage

Whenever you cast an artifact spell, draw a card.

Blinkmoth Urn

At the beginning of each player's first main phase, if Blinkmoth Urn is untapped, that player adds {C} for each artifact they control.

Tormod's Crypt

{T}, Sacrifice Tormod's Crypt: Exile target player's graveyard.

Urza, Lord High Artificer

When Urza, Lord High Artificer enters, create a 0/0 colorless Construct artifact creature token with "This creature gets +1/+1 for each artifact you control."
Tap an untapped artifact you control: Add {U}.
{5}: Shuffle your library, then exile the top card. Until end of turn, you may play that card without paying its mana cost.

Trinket Mage

When Trinket Mage enters, you may search your library for an artifact card with mana value 1 or less, reveal that card, put it into your hand, then shuffle.

Etherium Sculptor

Artifact spells you cast cost {1} less to cast.

Foundry Inspector

Trophy Mage

When Trophy Mage enters, you may search your library for an artifact card with mana value 3, reveal it, put it into your hand, then shuffle.

Sensei's Divining Top

{1}: Look at the top three cards of your library, then put them back in any order.
{T}: Draw a card, then put Sensei's Divining Top on top of its owner's library.

Padeem, Consul of Innovation

Artifacts you control have hexproof. (They can't be the targets of spells or abilities your opponents control.)
At the beginning of your upkeep, if you control the artifact with the highest mana value or tied for the highest mana value, draw a card.

Prophetic Prism

When Prophetic Prism enters, draw a card.
{1}, {T}: Add one mana of any color.

Universal Automaton

Changeling (This card is every creature type.)

Cloud Key

As Cloud Key enters, choose artifact, creature, enchantment, instant, or sorcery.
Spells you cast of the chosen type cost {1} less to cast.

Riddlesmith

Whenever you cast an artifact spell, you may draw a card. If you do, discard a card.

Spidersilk Net

Equipped creature gets +0/+2 and has reach. (It can block creatures with flying.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Meteor Golem

When Meteor Golem enters, destroy target nonland permanent an opponent controls.

Island

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Ichor Wellspring

When Ichor Wellspring enters or is put into a graveyard from the battlefield, draw a card.

Mirrodin Besieged

As Mirrodin Besieged enters, choose Mirran or Phyrexian.
• Mirran — Whenever you cast an artifact spell, create a 1/1 colorless Myr artifact creature token.
• Phyrexian — At the beginning of your end step, draw a card, then discard a card. Then if there are fifteen or more artifact cards in your graveyard, target opponent loses the game.

Welding Jar

Sacrifice Welding Jar: Regenerate target artifact.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Shimmer Myr

Flash
You may cast artifact spells as though they had flash.

Tribute Mage

When Tribute Mage enters, you may search your library for an artifact card with mana value 2, reveal that card, put it into your hand, then shuffle.

Mana Drain

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.