This program implements a near-Infrared Wavefront sensor (‘IWA) for the Keck II telescope adaptive optics (AO) system. AO systems correct atmospheric blurring, allowing ground-based telescopes to achieve images as sharp as telescopes in space. A bright guide star is needed to measure the atmospheric errors, and doing so in the infrared enables lower-mass and dust-obscured stars to be used. ‘IWA enables a broad range of new and unique science, from the detection and characterization of young extra-solar planets to tests of black hole physics. ‘IWA builds on recent successful Keck AO upgrades. These upgrades transform Keck II AO from a 2000s-era general purpose system to a state-of-the-art facility for high-resolution infrared astronomy. It is also the first step towards achieving even sharper images in visible light. The ‘IWA project supports student and postdoctoral training in astronomical instrumentation and mentoring for students using the upgraded system for their research. The image quality, contrast, and sky coverage of the Keck II AO system will be significantly improved by ‘IWA’s infrared wavefront sensing capabilities. ‘IWA includes a high-order pyramid wavefront sensor for AO using bright natural guide stars, a medium-order sensing mode for use with fainter natural guide stars, and a low-order sensing mode to support high sky coverage laser guide star AO. ‘IWA also includes a Zernike wavefront sensor to provide improved primary mirror phasing, benefitting all Kec