Worldcat Server

An MCP (Model Context Protocol) server for searching WorldCat, the world's largest library catalog — 500M+ records from 100,000+ libraries worldwide.

Built with FastMCP and the WorldCat Discovery API v2.

Tools

Tool	Description
worldcat_search	Search by keyword, title, author, subject, ISBN, ISSN, OCLC number, or advanced CQL
worldcat_get_record	Get full bibliographic record with LCSH, LC/Dewey classification, physical description
worldcat_get_editions	Find other editions and formats of a work (hardcover, ebook, translations)
worldcat_get_citations	Get formatted citations in APA, Chicago, Harvard, MLA, and Turabian
worldcat_search_by_subject	Search specifically by Library of Congress Subject Headings
worldcat_export_ris	Export results as RIS (for Zotero, EndNote, etc.)
worldcat_export_bibtex	Export results as BibTeX

Rich metadata

Records include:

• Library of Congress Subject Headings (LCSH)
• LC Classification and Dewey Decimal numbers
• Physical descriptions, edition statements
• Publisher, place, and date
• ISBN, ISSN, LCCN, OCLC numbers
• Summaries/abstracts and table of contents
• Online access URLs
• Edition counts across libraries

Setup

1. Get WorldCat API credentials

You need a WSKey with wcapi scope from the OCLC Developer Network. Institutional access through a library is typically required.

2. Install

cd worldcat-mcp-server
python3 -m venv venv
source venv/bin/activate
pip install -r requirements.txt

3. Add to Claude Desktop

Add this to your claude_desktop_config.json:

{
  "mcpServers": {
    "worldcat": {
      "command": "/path/to/worldcat-mcp-server/venv/bin/python",
      "args": ["/path/to/worldcat-mcp-server/server.py"],
      "env": {
        "WORLDCAT_API_KEY": "your-wskey",
        "WORLDCAT_API_SECRET": "your-wskey-secret"
      }
    }
  }
}

Or if using Claude Code CLI:

claude mcp add worldcat \
  /path/to/worldcat-mcp-server/venv/bin/python \
  /path/to/worldcat-mcp-server/server.py \
  -e WORLDCAT_API_KEY=your-wskey \
  -e WORLDCAT_API_SECRET=your-wskey-secret

Usage examples

• "Search WorldCat for books on the history of jazz"
• "Find the full record for OCLC number 1234567890"
• "What other editions exist for this book?"
• "Get an APA citation for this WorldCat record"
• "Search by LCSH subject heading 'African Americans -- History'"
• "Export these results as RIS for Zotero"

License

MIT