Joint work with Sophie Marques and Luca Mesiti. We develop a monadic approach to actions of internal categories. Given an internal category, we construct a monad on a slice whose algebras are the actions of that internal category. Then, we give a complete characterization of the monads that arise in this way; we call them generalized action monads. Finally, we prove that these monads yield a well-behaved notion of generalized descent. Download [here](https://arxiv.org/abs/2607.09595) 