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Matt's Second Brain

First session

After install, restart Claude Code so the new MCP loads. Confirm it’s there:

/mcp

You should see second-brain in the list. If not, see troubleshooting.

Try the discipline

Just talk to Claude about something it might have notes on:

“What’s our git workflow?”

If you’ve seeded Standards, Claude should answer with a citation:

Per Trilium Standards / Git Workflow (last updated 2026-04-25): all PRs target develop, never main. So I’ll branch off develop for this fix.

The cite-when-consulting rule is part of the discipline skill — it’s how you know Claude is actually using the brain rather than guessing.

Write your first note manually

The plugin ships a /matts-second-brain:remember skill. Use it to test the write path:

/matts-second-brain:remember decisions

Claude prompts for title + body, enforces the what / why / evidence structure for decisions and lessons (refuses to write a note that’s missing one of the three), and tags the result with #claude-brain so it surfaces in future brain_recall queries.

Let Claude write proactively

Once you trust the discipline, the bigger value is unprompted writes. After Claude resolves a non-obvious bug, expect:

I’m going to write this to Lessons Learned since the root cause wasn’t obvious from the diff. OK?

You confirm, the note lands in the brain, and next time someone (or Claude) hits the same class of bug, brain_recall surfaces it.

Troubleshooting

/mcp doesn’t show second-brain after install

  • Make sure you restarted Claude Code (the MCP list is loaded at startup).
  • Check ~/.claude.json has the second-brain entry under mcpServers.
  • Look for stderr output: run second-brain-mcp directly in a terminal — it should start cleanly.

brain_setup_check says backend unreachable

  • Trilium: confirm curl http://127.0.0.1:8787/api/health-check returns 200.
  • Obsidian: confirm BRAIN_OBSIDIAN_VAULT points at an existing directory.
  • Notion: confirm the integration has been shared on the root page (Page → Share → invite the integration).

brain_recall returns no results even after seeding

  • Confirm the root note exists (brain_setup_check will tell you).
  • For Trilium: notes need the claude-brain label. The seed taxonomy + brain_remember add it automatically. For notes you wrote manually, add the label in Trilium.