Librarians who work with collection data sometimes spend extensive time running reports or looking up information. At Temple University, we regularly check our own and other libraries’ holdings when reviewing lists of missing or damaged books in order to decide which to re-purchase. A recent switch to using API queries instead of manually looking up holdings in WorldCat or our ILS has nearly eliminated tedious and time-consuming look-up processes. An API is a protocol for transferring data between two databases or systems. A script, written in a language such as R or Python, queries the database and returns data to the user. This poster shows a query the presenter wrote using the R programming, which retrieved WorldCat holdings for 600 titles in less than 30 minutes. The poster also notes other recurring projects that rely on the Alma, Primo, and World Cat Search APIs and contains a short bibliography of resources for people who want to learn more about APIs.