The Cooper Hewitt API provides its users with access to the data of 215,000 items in their collection, along with information about the people, companies, and other organizations that were associated with them. This project tested how novice and expert API users interact with the Cooper Hewitt API website by conducting a usability study and eye-tracking. We provided several recommendations focused on improving how people locate the API website (discoverability), find API examples (readability), and learn to run a query (learnability).