OCLC WorldCat REST API for searching 500 million+ library holdings worldwide, accessing bibliographic records, finding library locations, and retrieving rich metadata for books, videos, music, and other media. Provides access to the WorldCat Search API, WorldCat Metadata API, WorldCat Knowledge Base API, and WorldCat Entities data API for libraries and developers building discovery and cataloging applications.

APIs.json: https://raw.githubusercontent.com/api-evangelist/worldcat/refs/heads/main/apis.yml

• Libraries
• Bibliographic Records
• WorldCat
• OCLC
• Cataloging
• Metadata
• Discovery
• Books
• Media
• Linked Data

• Created: 2026-06-13
• Modified: 2026-06-13

Search WorldCat and retrieve bibliographic records for cataloged items such as books, videos, music and more across 500 million+ holdings. Supports retrieval by OCLC number, ISBN, ISSN, and other identifiers. Also enables finding libraries holding specific items and identifying libraries committed to retention programs.

• Human URL: https://www.oclc.org/developer/api/oclc-apis/worldcat-search-api.en.html
• Base URL: https://americas.discovery.api.oclc.org/worldcat/search/v2

• Search
• Bibliographic Records
• WorldCat
• OCLC
• Libraries
• Holdings

• Documentation
• OpenAPI — OpenAPI Specification

Enables libraries to search, retrieve and maintain their bibliographic, local bibliographic, holdings, and local holdings data in WorldCat. Supports synchronizing local catalog data, discovering shared print retention information, and enhancing metadata quality across the network.

• Human URL: https://www.oclc.org/developer/api/oclc-apis/worldcat-metadata-api.en.html
• Base URL: https://metadata.api.oclc.org/worldcat

• Metadata
• Cataloging
• Holdings
• Bibliographic Records
• Libraries

• Documentation
• OpenAPI — OpenAPI Specification

Provides developer-level access to a library's information in the WorldCat Knowledge Base, combining data about a library's e-content with access through linking features. Supports OpenURL requests for matching citations and retrieving access links, and REST requests for browsing and searching library subscription resources.

• Human URL: https://www.oclc.org/developer/api/oclc-apis/worldcat-knowledge-base-api.en.html
• Base URL: https://worldcat.org/webservices/kb

• Knowledge Base
• E-resources
• OpenURL
• Libraries
• Subscriptions

• Documentation

Retrieve a set of properties and data for over 150 million WorldCat Entities using associated uniform resource identifiers (URIs). Supports linked data integration for local discovery applications, research and analysis, and monitoring updates to WorldCat Entities data.

• Human URL: https://www.oclc.org/developer/api/oclc-apis/worldcat-entities-data.en.html
• Base URL: https://id.oclc.org/worldcat/entity

• Entities
• Linked Data
• WorldCat
• Libraries
• Research

• Documentation
• OpenAPI — OpenAPI Specification

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• Documentation
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FN: Kin Lane Email: kin@apievangelist.com