1 Weapon or 2 Non weapon slots. (Only 1 NWP slot if character already has Panache).
Once trained in Weapon Finesse, a character can exploit the ability to use light weapons quickly and accurately, using their dexterity attack bonus for hit and damage modifiers in melee combat.
The following weapons can be used with weapon finesse:
Dagger, Knife, Stiletto, Rapier, Main-gauche, Sabre, Scimitar, Short-sword and Whip