  JWST's Near-Infrared Imager and Slitless Spectrograph (NIRISS) includes an
Aperture Masking Interferometry (AMI) mode designed to be used between
2.7{\mu}m and 4.8{\mu}m. At these wavelengths, it will have the highest angular
resolution of any mode on JWST, and, for faint targets, of any existing or
planned infrastructure. NIRISS AMI is uniquely suited to detect thermal
emission of young massive planets and will permit the characterization of the
mid-IR flux of exoplanets discovered by the GPI and SPHERE adaptive optics
surveys. It will also directly detect massive planets found by GAIA through
astrometric accelerations, providing the first opportunity ever to get both a
mass and a flux measurement for non-transiting giant planets. NIRISS AMI will
also enable the study of the nuclear environment of AGNs.
