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Library APIs (application programming interfaces) let you access structured information about library collections. To use an API, you construct a URL that sends a request. You can use your browser, a special app, or a programming language to send requests. 

LibraryCloud is the best API to start with, because it’s a centralized store of metadata from across Harvard’s various cataloging systems. To get started with LibraryCloud, open up a new browser tab and build the URL.

Learn more about Harvard Library APIs, or look up LibraryCloud field names and other details.
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Our chat reference and Research Appointment Request services are intended for Harvard affiliates. All others are welcome to submit questions using the form on this page.
We are happy to answer questions from all Harvard affiliates and from non-affiliates inquiring about the library's collections.
Unfortunately, we're unable to answer questions from the general public which are not directly related to Harvard Library services and collections.