Chemical inventories of planet formation are established in stellar nurseries, where ices accumulate on dust grains before stars and disks emerge. ALMA observations of protostars suggest that a substantial fraction of this interstellar ice inventory is inherited by planet-forming disks. Yet, meteoritic records reveal that some solids undergo significant thermal processing, reshaping the material available for planet formation. Understanding the balance between inheritance and processing therefore requires a joint view of the gas and ice reservoirs. In this talk, I will present recent JWST results from molecular clouds, protostars, and planet-forming disks that trace the evolving chemical inventory and element partitioning during the earliest stages of planet formation. I will then touch upon ongoing efforts to connect these findings with an ALMA large program investigating the formation and evolution of complex organic molecules.
