It is also spider-friendly as to its static pages. See robots.txt

Take the page URL for any work, add .json and you get bibliographic information, including the page URL(s) for the author(s).

For example,

    https://openlibrary.org/works/OL1234567W.json

All the page URLs for Works and Authors are available as gzip'd XML at

    https://openlibrary.org/static/sitemaps/