WorldCat Search API

Overview

WorldCat is the world's largest network of library content, aggregating catalogs from 10,000+ libraries across 170+ countries. The Search API provides access to 500M+ bibliographic records — books, journals, dissertations, media, and more — with holdings information showing which libraries own each item. Essential for interlibrary loan discovery, collection analysis, and comprehensive bibliographic searches. Requires a WSKey (free for non-commercial use).

Authentication

# Register at https://platform.worldcat.org/
# Obtain a WSKey (API key) for your application

# OAuth 2.0 client credentials flow
curl -X POST "https://oauth.oclc.org/token" \
  -u "$WSKEY_CLIENT_ID:$WSKEY_SECRET" \
  -d "grant_type=client_credentials&scope=wcapi"

API Endpoints