Kinetic Monte Carlo (kMC) is an essential tool in heterogeneous catalysis enabling the understanding of dominant reaction mechanisms and kinetic bottlenecks. Here we present MonteCoffee, which is a general-purpose object-oriented and programmable kMC application written in python. We outline the implementation and provide examples on how to perform simulations of reactions on surfaces and nanoparticles and how to simulate sorption isotherms in zeolites. By permitting flexible and fast code development, MonteCoffee is a valuable alternative to previous kMC implementations.