From Pathfinder #151: The Show Must Go On, which isn't enabled.

Reflexive Catch

FEAT 4

UNCOMMON ARCHETYPE CONCENTRATE MANIPULATE

Activity reaction

Prerequisites expert in Acrobatics; Juggler Dedication

Requirements The item or thrown weapon is of a Bulk you can Juggle. If the trigger was a thrown weapon attack targeting you, you can't be Off-Guard to the attack. If you were already Juggling, you can't be Juggling your maximum number of items.

Trigger An item falls within your reach or an attacker fails an attack roll to hit you or a creature within your reach with a thrown weapon.

You grab the triggering item. If you are Juggling, you can immediately add the item to the objects you're Juggling as a free action, which has the concentrate and manipulate traits.

Pathfinder #151: The Show Must Go OnOGL