aperta-accessum,which: i) harvests names and emails from adepartments faculty webpage, ii) identifies scholars’ Open Researcherand Contributor IDs (ORCID iDs), iii)obtains digital object identifiers (DOIs) of publications for each scholar, iv) checks for existingcopies in an institution’s OA repository, v) identifies the legal opportunitiesto provide OA versions of all of the articles not already in the OA repository,vi) sends authors emails requesting a simple upload of author manuscripts, andvii) adds link harvested metadata from DOIs with uploaded preprint into OArepository. The results of this study show that inthe administrative time needed to open access a single document manually, aperta-accessum can process approximatelyfive entire departments worth of peer-reviewed articles. Following best practices discussed, it is clear this open sourceOA harvester enables institutional library’s stewardship of OA knowledge on themass-scale for radically reduced costs.