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Matt's Second Brain

Install

TL;DR

Terminal window
# 1. Install the Claude Code plugin
/plugin install matts-second-brain


# 2. In any Claude session — runs the wizard
/matts-second-brain:install


# 3. Restart Claude Code so the new MCP loads

The wizard handles everything: backend selection, credential collection (with hidden input), taxonomy seeding, MCP registration. You answer prompts, it does the work.

What the wizard does

  1. Detects existing setup. If Trilium is already running locally, or you have an Obsidian vault path set, it reuses them.
  2. Collects credentials safely. ETAPI tokens / Notion tokens go through a hidden-input prompt — never echoed, never in shell history, never in argv.
  3. Seeds the root taxonomy. Creates Claude Memory with Standards, Decisions, Lessons Learned, Apps, Reviews, Drafts children. Idempotent — safe to re-run.
  4. Registers the MCP server in your ~/.claude.json so the brain_* tools become available.
  5. Optionally scans transcripts for repeated corrections you can promote to Standards (read-only — never auto-writes).

Manual install (if you’d rather)

If you don’t want to use the wizard, here’s what it actually does:

1. Install the plugin

The plugin lives in the claude-plugins marketplace. From any Claude Code session:

/plugin install matts-second-brain

2. Set up your backend

Pick one of:

Trilium (default — self-hosted)

Terminal window
# If you don't have Trilium yet:
docker run -d --name trilium -p 127.0.0.1:8787:8787 \
  -v trilium-data:/home/node/trilium-data \
  triliumnext/notes:v0.95.0

In Trilium UI: Options → ETAPI → Create new token. Copy the value.

Obsidian (local markdown vault)

Terminal window
export BRAIN_BACKEND=obsidian
export BRAIN_OBSIDIAN_VAULT="/path/to/your/vault"

Notion (cloud)

In Notion: create an integration at https://www.notion.so/profile/integrations, share a root page with the integration. Then:

Terminal window
export BRAIN_BACKEND=notion
export BRAIN_NOTION_TOKEN=secret_xxxxx
export BRAIN_NOTION_ROOT_PAGE=<root-page-id>

3. Install the MCP

Terminal window
npm install -g @matthesketh/second-brain-mcp

Add to ~/.claude.json:

{
  "mcpServers": {
    "second-brain": {
      "type": "stdio",
      "command": "second-brain-mcp",
      "env": {
        "BRAIN_BACKEND": "trilium",
        "TRILIUM_URL": "http://127.0.0.1:8787",
        "TRILIUM_ETAPI_TOKEN": "your-token-here"
      }
    }
  }
}

4. Seed the taxonomy

Restart Claude. In a session, say:

Run brain_seed_taxonomy.

That’s it.

Multi-user setup

If multiple OS users share one Claude/brain instance, see Multi-user setup.