You produce your artificer spell effects through your tools. You must have a spellcasting focus – specifically tinker’ tools or some kind of artisan’s tool – in hand when you cast any spell with this Spellcasting feature. You must be proficient with the tool to use it in this way.
After you gain the Infuse Item feature at 2nd level, you can also use any item bearing one of your infusions as a spellcasting focus.