katalogtjänst

A katalogtjänst is a software service that provides programmatic access to a catalog of resources, typically bibliographic records, but also product or media catalogs. It enables search, retrieval and often synchronization of metadata and, in libraries, information about item holdings and availability. A katalogtjänst is used to enable discovery across institutions, to feed library portals, discovery layers, or third‑party applications.

In library contexts, a katalogtjänst exposes metadata about bibliographic records—title, author, ISBN/ISSN, publisher, publication year, language, subjects—and item‑level holdings such as location, loan status, and available copies. Access is usually via standardized interfaces such as SRU/SRW (Search/Retrieve via URL), OpenSearch, or RESTful APIs, and the service returns records in formats such as JSON, XML, MARC, Dublin Core or MODS. It may also provide linking to full text or digital objects and support identifiers and authority data.

In commercial or digital repository contexts, katalogtjänsten may present product catalogs or asset catalogs, with search, filtering (facets), and metadata retrieval, including stock status and pricing where applicable. Data quality, deduplication, licensing, and provenance are important considerations.

Implementation approaches vary: some systems index records from a central catalog or national union catalog and expose them via a unified API; others aggregate results from multiple catalogs. Standards and protocols (Z39.50 historically; SRU/SRW; REST/GraphQL) support interoperability and integration with library systems, discovery layers, and external applications.

In Sweden, the term is commonly used for catalog services that connect local library catalogs to national or regional discovery layers, facilitating cross‑library search for patrons.