As one of the Digital Public Library of America (DPLA)’s largest service hubs, Mountain West Digital Library aggregates metadata from over 70 institutions in the US Intermountain West. How can we efficiently and comprehensively audit thousands of metadata records for digitized special collections? We meet this challenge through the adoption of a tool coded by a fellow DPLA hub, North Carolina Digital Heritage Center, that uses XSL to test OAI-PMH feeds against our local metadata application profile. Building on MWDL’s original 2015 adaptation, the past year brought further updates to the tool that broadened its capabilities to support auditing for a diverse range of repositories, including CONTENTdm, Islandora, Samvera, and Solphal. This talk will discuss the project, technical challenges, pros and cons, and future directions.