You have at least one instant and/or sorcery card in hand.
({4} magic symbol) ({U} magic symbol) , plus enough mana to pay for the nonland card's mana cost minus ({W} magic symbol) ({U} magic symbol) ({B} magic symbol) ({R} magic symbol) ({G} magic symbol) available.
Steps
Cast Aura Finesse by paying ({U} magic symbol) , attaching the Aura to Codie and drawing a card (this is necessary because Codie's ability forces you to cast the Aura before Codie is on the battlefield).
Activate the Aura by paying ({U} magic symbol) , untapping Codie.
Repeat from step 2 any number of times, skipping step 3 on the final iteration.
Once you have an arbitrarily large number of Codie triggers, cast any spell by paying its mana cost, reduced by the ({W} magic symbol) ({U} magic symbol) ({B} magic symbol) ({R} magic symbol) ({G} magic symbol) added in step 2.
Codie triggers for each time you activated its ability.
Resolve the first trigger, causing you to exile cards from the top of your library until you exile an instant or sorcery spell with lesser mana value, and allowing you to cast that spell without paying its mana cost.
Repeat step 7 for each remaining trigger.
You may also repeat this combo for each instant and/or sorcery card in your hand as mana permits, and on subsequent turns.
Results
Cast all instants and sorceries in your library with mana value less than instants and/or sorceries you cast.