librocat
Libro, the library cat, sitting on a bookOpen source · Apache-2.0 · Hosted coming soon

The open-source knowledge base for AI agents

One knowledge base every agent shares over MCP, managed by Libro, an AI librarian. Your agents write to it and read from it; Libro catalogs, cross-references, and weeds it with library science proven over centuries. It is an LLM wiki in Google's Open Knowledge Format: tell one agent once, and Claude, Cursor, Codex, and VS Code all know it, and know when it is out of date.

npx plugins add librocat/librocat

librocat Cloud opens soon. Any agent: npx librocat connect

View on GitHub See how it works

Not a database. A library for your agents. A database hands back the row you asked for. A library hands back the whole picture: what is related, what is current, what was retired.

decisions/agent-sign-in.md
---
type: Decision
title: Agents sign in with OAuth
description: No API keys: each agent signs in once.
tags: [auth, mcp]
status: stable
---
The browser opens on the first call, so
there is no key to leak.
See [kickoff](/notes/kickoff.md).

How it works

An LLM wiki with a librarian: your agents ingest and query, Libro checks the library.

01 · Ingest

Your agents write it

Nothing to upload. Say "read this doc, this page, this video: remember it" and your agent reads it with its own tools and writes concepts that cite the source: plain Markdown files with a short header, in librocat Cloud or in the librocat you self-host.

you
watch this talk, remember it
agent
4 concepts → talks/*.md · 12:34

02 · Maintain

Libro keeps it

Libro catalogs each concept, files it under your vocabulary, and flags what may be out of date or duplicated onto a review shelf. It proposes; you approve, and your agent does the rewriting. Every change is a revision you can read back.

libro
cataloged 3 · 1 past its review date
shelf
still true? · retire · merge

03 · Query

Every agent reads it

One MCP connection, the same tools everywhere. What one agent saves, every agent finds. Projects are shelves in one library, so nothing gets split. At librocat.dev/mcp, always the latest version, or at your self-hosted address.

agents
Claude · Cursor · VS Code
mcp
librocat.dev/mcp · sign in once

Tools

What your agent calls, and who can call it
Twenty tools, the same on librocat Cloud and on a self-hosted librocat. Any agent that speaks MCP connects.
The tools
Read
searchget_conceptlistneighborsgraphget_source
Write
ingestupdaterenamedeleteadd_source
Library
historyweed_reportchangedthesaurusfinding_aidstatus
Review
review_shelfproposedecide
Who can call them
Agents
Claude CodeCursorVS CodeCodexCopilot CLIOpenClawHermes AgentNemoClawand any remote MCP client, from any machine
Libro, the library cat

Managed by Libro

A librarian for the knowledge your agents share

A managed database has an operator. A managed knowledge base has a librarian. Libro, the library cat, is an AI agent that keeps librocat trustworthy: nothing stale left standing, nothing duplicated, nothing invented. Libro proposes; you decide.

Catalogs what arrives
Your agents write; Libro fills in the catalog record they left blank. It selects from the concept's own sentences and your tags, and writes nothing of its own: what nothing fits stays blank for your agent.
Keeps it current
Concepts past their review date, never read, or quietly replaced by a newer one go on the review shelf. You mark it still true, or retire it; either way the library remembers who checked.
Keeps it consistent
Two spellings of one tag become one. Two concepts about one subject go on the shelf; your agent drafts the merge, and Libro checks it against both.
Tells you what it shows
What arrived, what is stale, what your agents read most, what nobody reads. The dashboard is the library's report, kept current.

Library science · applied to agent knowledge

Organized the way libraries have organized knowledge for a century

025.3

Cataloging
Every concept gets a catalog record: type, title, one line on what it is, tags. Your agent writes it; what it leaves blank, Libro copies from the concept's own words and your tags, and marks what it supplied.

025.49

Controlled vocabulary
One word per idea. The thesaurus holds preferred tags, their synonyms, broader, narrower, and related terms, and a scope note that says what each tag covers.

025.4

Classification
Shelves group a project's concepts; a concept is filed under its most specific tag, and a search for a broad tag finds everything under it. Cutter's rules, from 1876, still hold.

025.322

Authority control
rename moves a concept and rewrites every link that points at it. Nothing breaks. Nothing goes missing.

025.216

Weeding
Stale knowledge is worse than none. Review dates, never-read concepts, and retired ones go on the weed_report, and Libro puts each on the review shelf.

025.52

Reference and finding aids
Every shelf has a finding aid, the list a librarian would hand you. Every search hit says whether it is past its review date, so an agent knows what to double-check.

Built on open standards

Andrej Karpathy
LLM Wiki
A wiki an LLM maintains: ingest, query, lint. Your agents ingest and query; Libro lints.
Google
Open Knowledge Format
Markdown with a short header, curated like code. Your export is plain OKF.
MCP
Model Context Protocol
How every agent reaches the library: one remote MCP, sign-in by OAuth.
agent-plugins.org · agentskills.io
Agent Plugins and Skills
One install gives an agent the connection and the skills to catalog well.

Two ways to start free: Cloud, or self-host

Open source either way, under Apache-2.0: the code that runs librocat Cloud is the code on GitHub. Either way, your agents connect the same way: Claude Code, Codex, Cursor, VS Code, and more.

librocat Cloud
Managed for you

One library for every agent on every machine, always the latest version, backed up and run for you. Each agent signs in once; no keys to copy. Libro, the library cat, catalogs what your agents leave blank and pulls duplicates and stale concepts onto a review shelf. Free to start; upgrade when you need more, or a team.

npx plugins add librocat/librocat
Self-host
Free. Docker. Yours.

The same site, dashboard, and MCP on your own server, with Docker or Podman, the way you self-host Supabase. No limits, no billing. You run it, bring your own models, and get help from the community.

git clone https://github.com/librocat/librocat.git
cd librocat/self-host && ./setup.sh

Then connect your agents: npx librocat connect --url https://your-host/mcp. Details in SELF_HOSTING.md.

Pricing

Start free with a library of 1,000 concepts. Individual is $12 a month per library: 5,000 concepts, and Libro reviews it every week. Team is $15 a person a month, for three people or more sharing one knowledge base. Pay for the year and get two months free. Plans are for librocat Cloud; self-hosting is free.

Free
$0
free, forever

One person, to start

  • Hosted MCP: every agent, every machine
  • 1 library, 1,000 concepts
  • 500 index credits a month: cataloging, and searching your files by meaning
  • Search by meaning (2,000/mo), then by words
  • Libro's review shelf: duplicates, review dates, gaps. Your agent works it with you
  • Attach anything: 100 MB of files and text, found by meaning
  • Revision history on every write
Individual
$10 /mo
$120 per library, billed once a year.
You save $24 per library.

One person, every agent and machine

  • Hosted MCP: every agent, every machine
  • 5,000 concepts
  • 500 index credits a month (cataloging and file search), then $0.01 each
  • Libro's review shelf and report, every week
  • Attach anything: 5 GB of files and text, found by meaning
  • A reading list, and source watch: cited pages re-checked weekly
  • Revision history on every write
  • Export or delete anytime
Team
Most popular
$12.50 /person/mo
$150 per person, billed once a year.
You save $30 per person.

A team, one shared knowledge base

  • 3 or more people, each with their own sign-in
  • 15,000 concepts
  • 2,500 index credits a month (cataloging and file search), then $0.01 each
  • Libro's review shelf and report, every week
  • Attach anything: 25 GB of files and text, shared by the team
  • A reading list, and source watch: cited pages re-checked weekly
  • Revision history + export anytime
Enterprise
Custom
priced to your needs

Larger organizations

  • Custom concept and user limits
  • SSO
  • Security review
  • Priority support

Export everything, anytime. Delete in one click. Cancel whenever. Your memory stays yours.

Prices are in US dollars. Sales tax or VAT is added at checkout where it applies.

Questions