> ## Documentation Index
> Fetch the complete documentation index at: https://aileadersvietnam.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Introduction

> Brain OS is a Claude Code plugin that gives you 25 AI-powered skills for managing a second brain in Obsidian — from processing books to running your day to deep thinking.

Brain OS is a Claude Code plugin for Obsidian-based second brain management. It installs as a set of skills that Claude Code can invoke directly, turning your vault into an active thinking and knowledge system rather than a static archive.

You get 25 skills across four categories, all reading from and writing to a structured Obsidian vault.

## What you need

* [Claude Code](https://docs.anthropic.com/en/docs/agents-and-tools/claude-code/overview) installed and running
* An Obsidian vault (or any markdown-based note system) with the [expected folder structure](/vault-setup)

## Skill categories

<CardGroup cols={2}>
  <Card title="Knowledge Pipeline" icon="book-open" href="/skills/self-learn">
    Process books end-to-end: extract, validate against NotebookLM, ingest into structured vault notes, and absorb deep insights. Skills include `self-learn`, `audit`, `chain`, `ingest`, `absorb`, and `book`.
  </Card>

  <Card title="Daily Operations" icon="calendar" href="/skills/today">
    Start and close your day with purpose. Morning review, end-of-day extraction, session handovers, and vault sync. Skills include `today`, `close`, `handover`, `pickup`, and `sync`.
  </Card>

  <Card title="Thinking Tools" icon="lightbulb" href="/skills/think">
    Deep thinking, idea surfacing, belief pressure-testing, and pattern discovery across your vault. Skills include `think`, `emerge`, `challenge`, `drift`, `connect`, `trace`, `ghost`, `ideas-gen`, and `graduate`.
  </Card>

  <Card title="Configuration" icon="gear" href="/configuration">
    Set your vault path, manage installation modes, configure the eval system, and install dependencies for book learning.
  </Card>
</CardGroup>

## Next step

Follow the [Quick Start](/quickstart) to install Brain OS and run your first skill in under five minutes.