WorldCat MCP 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

Related MCP server: OpenAlex MCP Server

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