We report a synthetic route for the production of water-sensitive metal-organic frameworks (MOFs), in polymer fiber sorbents by use of metal oxides as seeding intermediates. Cellulose acetate/ZnO (48 wt %) fibers were spun via a dry-jet wet-quench method and converted through hydroxy double salt (HDS) intermediates into HKUST-1 and ZIF-8. MOF loadings within the fiber sorbent reached 85 and 66 wt %, respectively. We demonstrate this process on module-packaged fibers, in which ready-to-use fiber sorbents are synthesized in a moisture-free environment. Modules are then employed in proof-of-concept CO2/N-2 breakthrough experiments.