Claude Can Now Read Thousands of Rare Books

Today we're releasing an MCP server that gives Claude direct access to Source Library. One command, no API key, and Claude can search, read, and cite thousands of historical texts — with full English translations and 110,000+ extracted illustrations.

MCP (Model Context Protocol) is an open standard that lets AI assistants connect to external data sources. Instead of pasting text into a chat window, you give Claude a set of tools — and it decides when and how to use them. The server now provides 15 tools covering search, full-text reading, verbatim citation, canonical-reference lookup, and image retrieval — plus ways to contribute findings back. (This post has been updated as the toolset has grown since launch; the list below is current.)

What you can do with it

The point isn't to query a database. It's to do research. Here are some things that now work naturally in a conversation with Claude:

Trace a concept across centuries

Claude searches the full text of every translated book, finds passages discussing prima materia in works spanning the 15th to 17th centuries, reads the relevant pages, and synthesizes a comparative analysis. It can pull the original Latin alongside the translation, showing you exactly what Sendivogius wrote versus what Basil Valentine wrote — with page numbers and links back to the source.

Follow a figure through the tradition

Source Library maintains a knowledge graph of entities — people, places, and concepts — linked across books. Hermes Trismegistus, for example, appears in 18 books with 441 total mentions, connecting:

• ●Ficino's Pymander — the 1471 translation that launched the Hermetic revival
• ●Copernicus's De Revolutionibus — which quotes Hermes on the Sun's centrality
• ●The Musaeum Hermeticum — 543 pages of alchemical texts under his name
• ●Kepler's Harmonices Mundi, the Fama Fraternitatis, Kircher's Musurgia Universalis, and more

Claude can follow these connections, read the relevant passages in each book, and show you how the figure of Hermes shifts from Ficino's prisca theologia to the Rosicrucian manifestos to Kircher's baroque syncretism — all grounded in the primary sources.

Read a book and ask questions

The get_book_text tool returns the complete text of a book — or a page range — in a single call. Claude can read 50 pages of the 1610 Sidereus Nuncius in both the original Latin and translation, then discuss the content as a reading partner who has actually read the text. This is the difference between searching about a book and reading the book.

Get a citation for your paper

The get_quote tool returns the passage alongside pre-formatted citations — inline, footnote, and bibliography formats — with DOI when available. Claude finds the relevant passage, gives you the Latin and English, and hands you a citation ready to paste into your paper.

Explore historical illustrations

Source Library has extracted and catalogued 90,000+ illustrations from its books — woodcuts, engravings, emblems, frontispieces, diagrams — each with AI-generated metadata including subject tags, depicted figures, symbols, and museum-style descriptions. Claude can search this gallery, find the images, identify which books they come from, and read the surrounding text to explain their context.

The collection

Source Library holds over 4,000 books digitized from 13 archives worldwide — the Internet Archive, Gallica, the Bodleian, the Vatican Library, the Bavarian State Library, and others. The collection focuses on the Western esoteric tradition broadly defined:

• ●Latin alchemical and Hermetic manuscripts (1450–1700)
• ●German mystical and Paracelsian works
• ●Renaissance philosophy — Ficino, Bruno, Pico, Agrippa
• ●Rosicrucian manifestos and related texts
• ●Early modern science — Copernicus, Galileo, Kepler
• ●Sanskrit, Chinese, Greek, Arabic, and Hebrew philosophical texts

Every book has been OCR'd from the original page images and translated to English by AI, with the original language always preserved alongside for verification. Published editions carry DOIs via Zenodo.

How it works

The MCP server runs locally on your machine and calls Source Library's public API. It doesn't need database credentials, API keys, or any configuration. When Claude needs to search for a book or read a passage, it calls the appropriate tool, the server makes an HTTP request to sourcelibrary.org/api, and the result comes back into the conversation.

The 15 tools are organized into five groups:

Install

The easiest path today needs no install at all: Source Library is in the Claude connector directory — switch it on from the connectors menu, or add https://sourcelibrary.org/api/mcp as a custom connector in any MCP client.

To run it locally instead — for Claude Code:

For Claude Desktop, add this to your config file (claude_desktop_config.json):

{
  "mcpServers": {
    "source-library": {
      "command": "npx",
      "args": ["-y", "@source-library/mcp-server"]
    }
  }
}

The server is open source and published on npm. Full documentation is on the developers page.