Player's Handbook
0-level (Cantrip) Transmutation
This spell repairs a single break or tear in an object you touch, such as a broken chain link, two halves of a broken key, a torn cloak, or a leaking wineskin. As long as the break or tear is no larger than 1 foot in any dimension, you mend it, leaving no trace of the former damage.
This spell can physically repair a magic item or construct, but the spell can’t restore magic to such an object.