In this talk, I will present how the aperture masking interferometric (AMI) mode of the JWST works. I will describe the main characteristics of this mode. In particular, I will show some of the advantages of the mode complementary to standard imaging and coronagraphic observations. I will also introduce the basic principles of the AMI data analysis, including the extraction of the interferometric observables and their interpretation with parametric models and image reconstruction. I will provide a quick overview on some of the early results obtained with this mode for a couple of Early Release Science programs with the JWST. Finally, I will present some of the new developments on interferometric image reconstruction for JWST/AMI.