/obsidian-second-brain

name: obsidian-second-brain
description: >
  Operate any Obsidian vault as a living, self-rewriting second brain (an evolution
  of Karpathy's LLM Wiki pattern: sources rewrite existing pages, contradictions
  reconcile automatically, scheduled agents maintain the vault while you sleep).
  Use this skill whenever
  the user asks Claude to read, write, update, search, or manage their Obsidian
  vault - including saving notes from conversation, creating daily entries, updating
  kanban boards, logging dev work, managing people notes, capturing decisions,
  tracking deals, or maintaining any vault structure. Also triggers when the user
  wants to bootstrap a new vault from scratch, run a vault health check, or drop
  a _CLAUDE.md into their vault so all Claude surfaces share the same operating rules.
  Also runs Crew (/crew): one shared logbook so Claude Code, Codex, Cursor, and Grok Bot
  know what each other did, in any plain folder or the vault.
  Includes a research toolkit (7 commands: /x-read, /x-pulse, /research, /research-deep,
  /notebooklm, /youtube, /podcast) for AI-powered research via Grok, Perplexity, NotebookLM,
  YouTube, and podcast feeds - findings save
  to the vault automatically following the AI-first vault rule. Use proactively whenever
  the conversation produces information worth preserving (decisions, people met, projects
  started, tasks completed, lessons learned, research findings).

Obsidian Second Brain

> Claude operates your Obsidian vault as a self-rewriting knowledge base. An evolution of [Karpathy's LLM Wiki pattern](https://gist.github.com/karpathy/442a6bf555914893e9891c11519de94f): sources rewrite existing pages instead of just appending, contradictions reconcile automatically, and scheduled agents maintain the vault while you sleep. > Everything worth remembering gets saved. Every update propagates everywhere it belongs.

---

Quick Start

0. Choose vault access method (in order of preference)

Try these methods in order. Use the first one available:

**Method 0 - SessionStart hook (if configured):** If `hooks/load_vault_context.py` is wired as a SessionStart hook in `~/.claude/settings.json`, `_CLAUDE.md` is injected into context automatically at session start. Skip step 1 only when the manual is actually in your context, not merely because the hook is configured. Claude Code caps hook context at 10,000 characters, so a larger manual cannot be injected; in that case the hook says so in as many words ("NOT loaded - read it") and you read the file yourself (#270). A vault whose `.claude/CLAUDE.md` holds `@../_CLAUDE.md` sidesteps the cap entirely - Claude Code imports that natively at any size. To wire it: `bash scripts/setup.sh "/path/to/vault"`. If another Obsidian plugin also holds a SessionStart hook, the injected context opens with a precedence note naming it (#300). Claude Code runs every SessionStart hook and adds each output here, so you may be holding two folder maps and two frontmatter schemas for one vault. The vault's own `_CLAUDE.md` governs every write. Where the other tooling disagrees, follow the manual and say so in your reply.

**Method A - Direct filesystem (default, always works):** Use standard file tools (Read, Write, Edit, Glob) against the vault path. The vault is plain markdown, so every operation in this skill works this way with no setup. This is the normal path in Claude Code - the commands below use these tools directly.

**Method B - MCP server (optional, mainly for non-Claude-Code clients):** This repo ships its own MCP server at `integrations/obsidian-mcp-server/` that exposes the vault as tools (`obsidian_search`, `obsidian_read_note`, `obsidian_save_note`, `obsidian_capture`, plus curator tools). It exists so other MCP clients - Hermes Agent, Claude Desktop, Cursor - can use the vault as a knowledge layer; in Claude Code itself, Method A is simpler and preferred. If those `obsidian_*` tools happen to be available in your client, you may use them instead of raw file tools. Setup lives in `integrations/obsidian-mcp-server/README.md` (it is `uv run --no-project --with 'mcp<2' python .../server.py` with `OBSIDIAN_VAULT_PATH` set, not an `npx` package). Since the bookkeeping change, every write through the server also validates the note, adds the index entry, appends the operation-log line, and runs `OBSIDIAN_POST_WRITE_CMD` when set - see `integrations/obsidian-mcp-server/README.md`, "Bookkeeping after writes".

1. First time in a vault → read `_CLAUDE.md`

Before doing anything in a vault, check if `_CLAUDE.md` exists at the vault root and read it:

Read <vault>/_CLAUDE.md

If it exists: follow its rules exactly - they override the defaults in this skill. Where `_CLAUDE.md` is silent, fall back to the defaults below. If it doesn't exist: use the defaults in this skill, then offer to create one.

Skip this step only if `_CLAUDE.md` is actually in your context already - the SessionStart hook injects it, but not when the manual is over Claude Code's 10,000-character hook limit, and the hook says which case you are in. If you cannot quote a rule from it, you do not have it: read the file.

2. First time with a new user → run discovery

Glob <vault>/**/*.md

Scan the structure to understand: folder names, template locations, naming conventions, frontmatter patterns. Then read 2-3 existing notes to calibrate writing style before creating anything new.

3. Bootstrap a new vault

If the user has no vault yet, bootstrap it from the local copy of the skill. The skill is already installed if you are reading this file, so never pipe a remote install script into a shell on the user's behalf.

python scripts/bootstrap_vault.py --path ~/path/to/vault --name "Your Name"

# With a preset:
python scripts/bootstrap_vault.py --path ~/my-vault --name "Your Name" --preset executive
python scripts/bootstrap_vault.py --path ~/my-vault --name "Your Name" --preset builder
python scripts/bootstrap_v