For Developers & AI

The easiest path: just ask Claude

You don't need to install anything to use this collection with an AI. Open Claude (or any assistant with web access) and ask it to look something up on sourcelibrary.org — it will search, read pages, and quote with citation links. No SDK, no key, no setup.

For richer, structured access — semantic search, 50-page bulk reads, image search, DOI-backed citations — install the MCP server below or call the API directly.

30-second start (API)

One endpoint, no key required to begin. It speaks JSON-RPC over HTTP, so anything that can POST JSON can talk to it.

curl -X POST https://sourcelibrary.org/api/mcp \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0", "id": 1,
    "method": "tools/call",
    "params": {
      "name": "search_concept",
      "arguments": { "query": "prima materia", "limit": 5 }
    }
  }'

fetch('https://sourcelibrary.org/api/mcp', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    jsonrpc: '2.0', id: 1,
    method: 'tools/call',
    params: {
      name: 'search_concept',
      arguments: { query: 'prima materia', limit: 5 }
    }
  })
}).then(r => r.json()).then(console.log)

CORS is open (Access-Control-Allow-Origin: *) — paste the snippet above into any browser console and it works.

MCP Server

Gives Claude (and any MCP client) direct access to the full collection — search, read, quote, and browse 150,000+ illustrations. The endpoint is plain JSON-RPC over HTTP, so you can also call it from any HTTP client without an MCP library (see the snippets above). Pick whichever path fits.

claude mcp add source-library https://sourcelibrary.org/api/mcp

{
  "mcpServers": {
    "source-library": {
      "url": "https://sourcelibrary.org/api/mcp"
    }
  }
}

claude mcp add source-library -- npx -y @source-library/mcp-server

Tools

Try asking Claude

Command Line

Same tools as the MCP server, but standalone with colored terminal output. Add --json for scripts.

# Install
npm install -g @source-library/mcp-server

# Search the collection
source-library search "Paracelsus" --language=German

# Search inside translations
source-library translations "harmony of the spheres"

# Read a book
source-library text history-of-both-worlds-macrocosm-fludd --from=1 --to=50

# Get exact text for quoting
source-library quote history-of-both-worlds-macrocosm-fludd 57

# Browse illustrations
source-library images --subject=alchemy --type=emblem

# JSON output for piping
source-library search "alchemy" --json | jq .results

REST API

Direct HTTP access, no authentication. The MCP server and CLI use these same endpoints.

Bulk dataset access

Pulling OCR text, translations, or page-level data in bulk? That tier is keyed — use the form above to request one, or email us with what you're building. Reviewed within 24 hours.

Citation URLs

Every page includes a citation URL linking directly to the source. Published editions have DOIs via Zenodo.