I introduce DarkNews, a fast Monte Carlo generator based on vegas for neutrino upscattering, trident scattering, and other leptonic processes at accelerator neutrino experiments. We simulate the production of lepton pairs and photons from the decay or exchange of new particles in neutrino-nucleus scattering. Pre-defined new-physics models include heavy neutral leptons with new scalar and vector interactions, transition magnetic moments, and leptophilic Z’ mediator. Some pre-defined experimental setups include detectors in the BNB, NuMI, and J-PARC beams, and future experiments, like DUNE and FASERnu.