  In this Snowmass contribution we present a comprehensive status update on the
progress and plans for the proposed CODEX-b detector, intended to search for
long-lived particles beyond the Standard Model. We review the physics case for
the proposal and present recent progress on optimization strategies for the
detector and shielding design, as well as the development of new fast and full
simulation frameworks. A summary of the technical design for a smaller
demonstrator detector (CODEX-$\beta$) for the upcoming Run~3 of the LHC is also
discussed, alongside the road towards realization of the full experiment at the
High-Luminosity LHC.
