New WorldCat Metadata API 2.0 is now available

OCLC has announced the availability of WorldCat Metadata API 2.0. This upgraded version offers new functionality, like the ability to read and write Local Holdings Records (LHRs), including registering shared print commitments; search WorldCat and receive single best-match WorldCat bibliographic record from multiple matches; and search Local Bibliographic Data (LBD) records on a variety of indexes, as well as by OCLC Number or control number. In addition to new functionality, users of WorldCat Metadata API 2.0 benefit from the new API infrastructure, greater interoperability, and enhanced security features.

WorldCat Metadata 2.0 provides bidirectional access to WorldCat, allowing users to create and interact with MARC records as well as access information about Local Holdings Records (LHRs). The API builds on functionality that was introduced in WorldCat Metadata API 1.1—like the ability to search WorldCat on a variety of indexes rather than only by OCLC Number—and is available to libraries who maintain an OCLC Cataloging & Metadata Subscription.

To compare functionality of WorldCat Metadata API versions 1.x and 2.0, please see the functionality comparison table. Libraries with an existing API key for WorldCat Metadata API 1.x can use that key to access WorldCat Metadata API 2.0. If a library does not have an existing API key, one can be requested on the API Keys page. Current users of WorldCat Metadata API 1.x are encouraged to upgrade now, as WorldCat Metadata API 1.x will be decommissioned on 30 April 2024. 

Upgrade to WorldCat Metadata API 2.0


Leveraging a scalable infrastructure, OCLC APIs share fundamental building blocks, like design patterns and authentication, to create a more seamless experience across OCLC services. This API-first strategy allows for more capabilities and data accessibility via APIs so our developer community can build custom solutions and integrations more easily.

  • Karen Coombs

    Karen Coombs

    Senior Product Analyst