MARC records via API
You can get all book MARC records from the Metadata Downloader via a public API.
The eISBN attribute is sometimes called Online ISBN. We only support MARC XML records, not MARC21 records.
KBART metadata via API
We are currently unable to offer an API for institution-specific entitlement holdings data, or for information in KBART format. If your institution would like to raise interest for this feature, please contact our Online Service team at firstname.lastname@example.org to communicate this.