librarian
Enables browsing, searching, and quote verification of a local ebook library via MCP, providing deterministic RAG with no embeddings or network.
README
<!-- mcp-name: io.github.Terobyte/librarian -->
📚 librarian
Turn any ebook into clean, token-counted Markdown chapters — let Claude read your bookshelf over MCP and catch it misquoting your books. Deterministic RAG: no embeddings, no network, no API keys.

Any input format — FB2, EPUB, DOCX, HTML, TXT/MD, text-layer PDF — becomes a directory of clean chapters with token counts. No network, no LLM, no randomness: the same input always produces byte-identical output.
Install
uv tool install librarian-cli
# or: pipx install librarian-cli
Offline contract: install and runtime need no network (the tokenizer's vocabulary is vendored in the package).
Quick start
lib ingest examples/*.epub
lib list
lib find curiouser
lib get <book-id> --budget 3000
Commands
| Command | Purpose |
|---|---|
lib ingest <files…> [--force] [--no-keep-source] [--config cfg.toml] [--verbose] |
Process books into the library; prints a file · id · status · score table. |
lib list [<book-id>] |
No argument — all books; with an id — that book's chapters (n, title, tokens, summary). |
lib get <book-id> <spec> |
Print chapters by range (1-3,7) to stdout. |
lib get <book-id> --budget N [--from K] |
Greedily print consecutive chapters from K while the token sum stays ≤ N. |
lib find <query> [--limit 10] [--book <id>] [--reindex] [--json] |
Full-text search across chapters and titles/authors library-wide (bm25, snippets, RU/EN stemming). |
lib info <book-id> |
JSON: book metadata + quality metrics. |
lib doctor [<book-id>] |
No id — books in review and broken directories; with id — that book's report. |
lib reingest --all [--config cfg.toml] [--verbose] |
Rebuild the library from source/ with the current code/config. |
lib rm <book-id> |
Delete a book and rebuild the index. |
lib serve [--library <path>] |
Stdio MCP server over the library. |
lib verify "quote" [--book ID] [--json] [--limit N] |
Check a quote against one book or attribute it across the library. |
Library root: --library <path> (or the LIB_HOME env var, default ./library). Data goes
to stdout, diagnostics to stderr. Exit codes: 0 success, 1 runtime error, 2 usage error.
Give Claude your bookshelf
librarian-cli ships a built-in stdio MCP server with 6 read-only tools — list_books,
list_chapters, find, get_chapters, book_info, verify_quote — so Claude can browse
the catalog, search it, pull chapters under a token budget, and check its own quotes against
the source on its own: deterministic RAG with no embeddings, no network, and no API keys.
Claude Code:
claude mcp add librarian --env LIB_HOME=$HOME/books -- uvx librarian-cli
Claude Desktop (claude_desktop_config.json):
{
"mcpServers": {
"librarian": {
"command": "uvx",
"args": ["librarian-cli"],
"env": { "LIB_HOME": "/path/to/books" }
}
}
}
Verify quotes
An MCP server that catches Claude misquoting your books.
lib verify "quote" checks whether a quote actually appears in your library, verbatim —
punctuation, case, ё/е, and markdown formatting don't count. Two modes:
- Book mode (
--book <id>): full scan of one book — "does this book actually say this?" Works without the search index. - Shelf mode (no
--book): attribution across the whole library via FTS5 candidates — "which book is this from?" The quote needs at least 5 significant words (stop words don't count), or the check is skipped withverdict: null.
lib verify "Рукописи не горят" --book bulgakov-master-i-margarita
lib verify "рукописи не горят никогда"
| verdict | meaning |
|---|---|
exact |
matches after normalization (punctuation/case/ё/typography don't count) |
close |
similarity ≥ 0.95 — near-exact, differences shown as a word-diff |
distorted |
similarity ≥ 0.75 — the right place, but the quote is misremembered |
not_found |
similarity < 0.75 — nothing like it in the book/library |
null |
check wasn't run: empty quote, or a short quote without --book |
Exit codes (grep-style semantics, a deliberate departure from the project's usual
"1 = runtime error" — see docs/MILESTONES.md deviation 38):
| exit | case | stdout |
|---|---|---|
| 0 | exact / close — quote confirmed |
full report / JSON |
| 1 | distorted / not_found — not confirmed |
full report / JSON |
| 1 | runtime error (unknown book id, no search index, locked index) | empty |
| 2 | usage error: empty/short quote (verdict: null), --limit < 1 |
empty (message on stderr) |
Script discriminator: exit 1 with non-empty stdout means "checked, not confirmed"; exit
1 with empty stdout means an error (diagnostics went to stderr instead). Exit 0
includes close — a strict CI gate must check verdict == "exact" in the --json
output, not the exit code alone.
Quality
Every book gets a score from five metrics (coverage, structure, garbage, encoding,
dehyphenation): ok (score ≥ 0.90, no hard triggers) — saved silently; review
(0.60 ≤ score < 0.90, or triggers present) — saved with a warning, details via
lib doctor <id>; failed (score < 0.60) — not saved. Scans and password-protected PDFs
honestly fail (OCR and DRM removal are out of scope).
Determinism
The pipeline has no network access, no LLM calls, and no randomness — the same input file
always produces byte-identical output. That makes ingestion reproducible and cacheable, and
it's what makes lib serve's RAG deterministic: no embeddings to drift, no model calls to
vary between runs.
Limitations
- PDF: works well on typographically normal books; complex layouts may land in
review. - DRM is not circumvented; source legality is the user's responsibility.
- Networked filesystems (NFS/SMB) are not supported (the advisory lock isn't reliable there).
- MOBI/DJVU and text-less scans are not supported (v3 candidates: OCR, calibre).
- CLI messages are currently in Russian; English output is planned.
lib verify: quotes spanning a chapter boundary are not supported (v1) — the best you'll get isdistortedon one half.lib verify:closeon a single-word replacement is realistic from ~150 characters of quote; shorter quotes with a replaced word honestly land indistorted— a third of a three-word quote really is a distortion.lib verifyshelf mode (no--book) needs the FTS5 search index; book mode (--book <id>) works without it in the CLI.lib serveas a whole still requires FTS5 — it syncs the index at startup regardless of which tool gets called.lib verifyin book mode scans the whole chapter text in pure Python; a long book can take a few seconds of CPU. The MCP tool runs it in a worker thread so it doesn't block the rest of the server.
Русская версия
See README.ru.md for the Russian documentation.
Recommended Servers
playwright-mcp
A Model Context Protocol server that enables LLMs to interact with web pages through structured accessibility snapshots without requiring vision models or screenshots.
Magic Component Platform (MCP)
An AI-powered tool that generates modern UI components from natural language descriptions, integrating with popular IDEs to streamline UI development workflow.
Audiense Insights MCP Server
Enables interaction with Audiense Insights accounts via the Model Context Protocol, facilitating the extraction and analysis of marketing insights and audience data including demographics, behavior, and influencer engagement.
VeyraX MCP
Single MCP tool to connect all your favorite tools: Gmail, Calendar and 40 more.
graphlit-mcp-server
The Model Context Protocol (MCP) Server enables integration between MCP clients and the Graphlit service. Ingest anything from Slack to Gmail to podcast feeds, in addition to web crawling, into a Graphlit project - and then retrieve relevant contents from the MCP client.
Kagi MCP Server
An MCP server that integrates Kagi search capabilities with Claude AI, enabling Claude to perform real-time web searches when answering questions that require up-to-date information.
E2B
Using MCP to run code via e2b.
Neon Database
MCP server for interacting with Neon Management API and databases
Exa Search
A Model Context Protocol (MCP) server lets AI assistants like Claude use the Exa AI Search API for web searches. This setup allows AI models to get real-time web information in a safe and controlled way.
Qdrant Server
This repository is an example of how to create a MCP server for Qdrant, a vector search engine.