opds-mcp

An MCP server that lets an LLM browse, search and download books from OPDS catalogs (Open Publication Distribution System) — the Atom/JSON-based feed format used by digital libraries such as Project Gutenberg, Standard Ebooks, Feedbooks, and many self-hosted book servers (Calibre-Web, COPS, KOReader sync targets, etc).

Supports both OPDS 1.x (Atom + XML) and OPDS 2.0 (JSON) catalogs, OpenSearch-based full-text search, and downloading acquisition links to disk.

Tools

• opds_browse — fetch a catalog/feed document and return its navigation links (search, next/prev, subsections, facets) plus entries (title, authors, summary, categories, acquisition links, cover images).
• opds_search — search a catalog. Give it either the catalog's feed URL (its rel="search" link is discovered automatically) or an OpenSearch description URL directly, plus a free-text query.
• opds_get_entry — fetch a single entry/publication document (e.g. an entry's rel="alternate" link) for full details.
• opds_download — download the file behind an acquisition link to a local directory and return the saved file path.

All tools accept optional username/password for catalogs that require HTTP Basic Auth. The url argument of opds_browse/opds_search/opds_get_entry is optional if the server is configured with a default catalog via OPDS_BASE_URL (see below) — pass url explicitly to browse a different catalog for that one call.

Install

npm install
npm run build

Configure in an MCP client

Via npx (no local checkout required)

The package hasn't been published to the npm registry, but npx can install and run it straight from this GitHub repo — it clones the repo, runs npm install (which triggers the prepare script to build dist/), then executes the opds-mcp bin:

{
  "mcpServers": {
    "opds": {
      "command": "npx",
      "args": ["-y", "github:pastukhov/opds-mcp"],
      "env": {
        "OPDS_BASE_URL": "https://example.com/opds/root.xml",
        "OPDS_USERNAME": "optional-default-username",
        "OPDS_PASSWORD": "optional-default-password",
        "OPDS_DOWNLOAD_DIR": "/absolute/path/to/save/books"
      }
    }
  }
}

To pin a specific branch or commit, append it: "github:pastukhov/opds-mcp#branch-or-sha".

Via a local checkout

Example for Claude Desktop / Claude Code (claude_desktop_config.json or .mcp.json):

{
  "mcpServers": {
    "opds": {
      "command": "npx",
      "args": ["-y", "/absolute/path/to/opds-mcp"],
      "env": {
        "OPDS_BASE_URL": "https://example.com/opds/root.xml",
        "OPDS_USERNAME": "optional-default-username",
        "OPDS_PASSWORD": "optional-default-password",
        "OPDS_DOWNLOAD_DIR": "/absolute/path/to/save/books"
      }
    }
  }
}

npx -y /absolute/path installs dependencies and builds on first run, same as the GitHub form above. Alternatively, run npm install && npm run build yourself and point command/args directly at node and dist/index.js.

• OPDS_BASE_URL — the catalog opds_browse/opds_search/opds_get_entry use when a tool call doesn't pass its own url. This is the recommended way to point the server at a specific library (e.g. https://your-library.example/opds) without relying on the model to know or guess the address; omit it to require an explicit url on every call instead.
• OPDS_USERNAME/OPDS_PASSWORD — used as a fallback whenever a tool call doesn't pass its own credentials, which is convenient when the server is dedicated to a single authenticated catalog.
• OPDS_DOWNLOAD_DIR — where opds_download saves files; defaults to a directory under the OS temp folder.

Example flow

1. opds_browse with the catalog's root URL to see navigation links and/or a first page of entries.
2. opds_search with that same root URL and a query to find a specific book.
3. Pick an entry's acquisitions[].href from the result and pass it to opds_download to save the file locally (or use opds_get_entry first if you need more detail than the search result already includes).

Development

npm run dev            # run the server directly with tsx
npm run typecheck      # tsc --noEmit
npm test               # vitest, using fixture OPDS documents under fixtures/
npm run test:coverage  # vitest with a coverage report under coverage/
npm run build          # compile to dist/

Every pull request runs typecheck, build and test:coverage via .github/workflows/ci.yml. On every push to main, .github/workflows/coverage-badge.yml recomputes coverage and commits .github/badges/coverage.json, which the badge at the top of this file reads via shields.io's endpoint badge.

Notes

• Only http:/https: URLs are accepted; other schemes are rejected before any request is made.
• Downloaded files are capped at 200MB by default and written under a sanitized filename inside the configured download directory.
• Because feed documents can be arbitrarily large, opds_browse/opds_search return whatever a single page contains; use the navigation.next link from the response to page through the rest of the catalog.