Book Downloader MCP

Ask your AI for a book, get the file.

A Model Context Protocol server for Library Genesis (LibGen+). Search, resolve and download ebooks from Claude, Cursor, VS Code, Windsurf, Zed or any other MCP client — with automatic mirror discovery, MD5 verification and bounded concurrency.

You: Find me "The Art of War" and download it.
Claude: → libgen_search(query: "the art of war")
        25 results. → libgen_download(md5: "07fa8b41…")
        Saved /Users/you/Books/The Art of War.pdf (58 MB, md5 verified).

Contents

• Why this server

• Quick start

• Tools

• Example prompts

• Configuration

• Docker

• Programmatic API

• Development

• Troubleshooting

• Legal

Related MCP server: find-a-book-mcp

Why this server

• It actually works in 2026. LibGen+ mirrors answer non-browser user agents with a stock nginx page, so most scrapers look like the site is down. This server sends real browser headers, then verifies a mirror by running a live search rather than trusting a 200.

• Mirrors die constantly. Every configured mirror is probed with a real request; the warm mirror is re-probed and rotated automatically when a call fails.

• Downloads you can trust. Files stream to disk with a size cap, a .part file, and an MD5 check against the LibGen record. Existing files are never silently overwritten.

• Safe by construction. Filenames are sanitized (including Windows reserved names and traversal attempts), and the server refuses expired-key HTML pages instead of saving them as .pdf.

• Made for agents. Seven focused, snake_case tools with Zod-validated inputs and actionable error messages, plus a --status CLI probe for when a tool call fails.

Quick start

The package runs on demand through npx; there is nothing to install globally.

Claude Code

claude mcp add libgen \
  --env LIBGEN_DOWNLOAD_DIR=~/Books \
  -- npx -y book-downloader-mcp

Claude Desktop (claude_desktop_config.json)

{
  "mcpServers": {
    "libgen": {
      "command": "npx",
      "args": ["-y", "book-downloader-mcp"],
      "env": {
        "LIBGEN_DOWNLOAD_DIR": "~/Books"
      }
    }
  }
}

Cursor (~/.cursor/mcp.json), Windsurf (~/.codeium/windsurf/mcp_config.json) and Cline use the same shape:

{
  "mcpServers": {
    "libgen": {
      "command": "npx",
      "args": ["-y", "book-downloader-mcp"]
    }
  }
}

VS Code (.vscode/mcp.json)

{
  "servers": {
    "libgen": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "book-downloader-mcp"]
    }
  }
}

Anything else — the generic stdio snippet:

{
  "command": "npx",
  "args": ["-y", "book-downloader-mcp"]
}

Check mirror health before wiring it into a client:

npx -y book-downloader-mcp --status

Tools

Search results carry title, authors, publisher, year, language, pages, size, extension, md5 and mirrorUrl. Downloads return status, path, filename, bytes and md5Verified.

Set LIBGEN_DOWNLOAD_DIR once, or pass downloadDir per call. Relative paths resolve against the server's working directory.

Example prompts

• “Search LibGen for the 3rd edition of Computer Networks by Tanenbaum.”

• “Find an EPUB of Dune and download the smallest result.”

• “Download these five books into ~/Research/Books.”

• “LibGen search is failing — check the mirrors and switch to a working one.”

• “Get me the direct download link for this md5, I'll use curl.”

Configuration

All settings are environment variables; each has a safe default.

CLI flags: --status (probe mirrors and exit), --version, --help.

Docker

docker build -t book-downloader-mcp .

# Mount a folder so downloads persist outside the container
docker run -i --rm \
  -v "$HOME/Books:/books" \
  -e LIBGEN_DOWNLOAD_DIR=/books \
  book-downloader-mcp

Mount a host folder to keep downloads after the container exits; the image defaults LIBGEN_DOWNLOAD_DIR to /books.

Programmatic API

import { LibgenClient, searchBooks, downloadByMd5, downloadByMd5List } from "book-downloader-mcp";

// One-off helpers (each creates a client)
const results = await searchBooks("the art of war", 1, 10);
const best = results.find((entry) => entry.extension === "pdf");

if (best?.md5) {
  const outcome = await downloadByMd5(best.md5, { downloadDir: "~/Books" });
  console.log(outcome.status, outcome.path, outcome.md5Verified);
}

// Reuse one client to keep the warm mirror and config cache
const client = new LibgenClient();
const status = await client.status();
const outcomes = await client.downloadMany(
  results.flatMap((entry) => (entry.md5 ? [entry.md5] : [])).slice(0, 3),
  { concurrency: 2 }
);

Useful exports: LibgenClient, createServer, TOOLS, loadConfig, HttpClient, LibgenPlusAdapter, LibgenError, searchBooks, downloadByMd5, downloadByMd5List.

Development

npm install
npm run dev            # run the server from source with reload
npm test               # 50 vitest tests
npm run test:coverage
npm run typecheck
npm run lint
npm run build          # emit dist/ and .d.ts
node dist/cli.js --status

Project layout:

src/
  cli.ts               CLI entry point (stdio server, --status)
  config.ts            Environment parsing
  libgen.ts            Client: mirror discovery, search, download, bulk
  core/                HTTP (browser headers, retries), files, errors
  api/                 Mirror config, HTML parsing, LibGen+ adapter
  mcp/                 MCPServer factory and the seven tool definitions
tests/                 Adapter, HTTP, config, files, client and MCP tests

Pull requests are welcome. Run npm run lint && npm test && npm run build before opening one.

Troubleshooting

Legal

This project only provides a client for Library Genesis mirrors operated by third parties. It does not host, mirror or distribute any content. Downloading copyrighted material without permission may be illegal where you live — you are responsible for what you download. The original project is obsfx/libgen-downloader.

License

WTFPL © Ömercan Balandı, with maintenance by Abhinav Prabhakar.