WorldCat doesn't have an official API for anyone but member libraries, scraping the site is not fun, and the quality of the data isn't great (it's essentially b

WorldCat doesn't have an official API for anyone but member libraries, scraping the site is not fun, and the quality of the data isn't great (it's essentially bulk-imported from member libraries' catalogs). National databases like the Library of Congress are significantly better - WorldCat is best used as a fallback for books that aren't included in the high-quality databases.