openurl

OpenURL is a standardized method for encoding bibliographic metadata and service requests in a URL to enable context-sensitive linking to scholarly resources. It is used by libraries, publishers, and discovery systems to connect a user’s request with the most relevant options for full text, metadata, or other services.

How it works

An OpenURL request consists of a base resolver URL followed by a set of query parameters that carry a ContextObject. Key components include url_ver and ctx_ver to indicate versions, ctx_enc for character encoding, and a set of rft.* parameters that describe the referent, such as rft.title, rft.au (author), rft.jtitle (journal title), rft.volume, rft.issue, rft.pages, and rft.date. Additional fields like rft_id or rft_val_fmt may identify specific items or formats. The resolver uses this metadata to determine which links to present, such as access to the publisher’s site, a library’s holdings, or alternative access options.

History and standardization

OpenURL was developed by researchers and libraries to improve automated linking within scholarly workflows and is standardized by the National Information Standards Organization (NISO) as part of the OpenURL framework. In practice, libraries commonly deploy OpenURL resolvers (for example, link resolvers such as SFX or similar systems) to deliver relevant access options directly from discovery interfaces or citation tools.

Applications and scope

OpenURL is widely used in library catalogs, discovery layers, and publisher platforms to enable interoperable linking across diverse systems. It supports a range of resource types and can be extended with additional metadata. Limitations include the need for consistent metadata and cooperative resolver infrastructure, but it remains a foundational mechanism for context-aware scholarly linking.