Right now there are no Wizards in Builders Base, which means there are no spells. Instead, we have a few troops and the one builder gives them special abilities. That said, we want spells inside of Builders Base Island.
Most likely these are coming at some point, as Supercell needs room to grow and improve this new aspect with future updates.
We've heard ideas for a "Revealer spell" that's extremely expensive, yet valuable. This would show Hidden Teslas or bombs and traps on bases. Although this would really change attack strategies and ruin the idea behind the creative base designs we use.
Another one is a "Targeting Spell" where we can direct any and all troops to specific targets for a small amount of time, like 10 seconds. This would mess up the mechanics of attacks and funneling, so it's doubtful. Either way, we'd love to see new spells or existing spells added to Builders Base.