Developer Resources


In keeping with the goal of the Digital Government Strategy to deliver better digital services to the American people, the Office of the Historian has created its first public Application Programming Interface (API) and has established this page to house information for developers. We invite developers to use our API and provide feedback.

Ebook Catalog API

The Office of the Historian Ebook Catalog API is a RESTful, OPDS-formatted catalog of the growing number of free ebooks from the Foreign Relations of the United States series. Use this API to embed our live, up-to-date, searchable, and browsable ebook catalog in your application and to locate download links to the ebooks and their cover images.


Developers are welcome to visit our organizational account on GitHub. Requests or inquiries may be submitted as issues.

Technologies & Standards

This website is powered by eXist-db, a free, open source XML server and the open standard W3C technologies it supports, including XQuery 3.0, EXPath, and EXQuery.

Our digitization initiatives center around the Text Encoding Initiative (TEI), an open, mature, XML-based standard used widely in libraries and the humanities. All our article- and book-length content is encoded as TEI. A single digital master TEI file can store an entire FRUS volume. We store this TEI in eXist-db and convert it to TEI into HTML or ebook forms using XQuery.

Our ebook catalog API uses the Open Publication Distribution System (OPDS), an Atom XML-based standard for encoding ebook catalogs.