| name | brain |
| description | Read/write brain files (Obsidian vault at brain/). Use for any task that persists knowledge — reflection, planning, or direct edits. Triggers: brain/ modifications, "add to brain". |
Brain
Persistent memory across sessions. Obsidian vault at brain/.
The brain is the foundation of the entire workflow — every agent, skill, and session reads it. Low-quality or speculative content degrades everything downstream. Before adding anything, ask: "Does this genuinely improve how the system operates?" If the answer isn't a clear yes, don't write it.
Before Writing
Read brain/index.md first. Then read the relevant entrypoint for your topic:
brain/principles.md for principle updates
For directories without a dedicated index file yet, scan nearby files directly and edit an existing note when possible.
Structure
brain/
├── index.md <- root entry point, links to everything
├── principles.md <- index for principles/
├── principles/ <- engineering and design principles
├── codebase/ <- project-specific knowledge and gotchas
└── plans/ <- feature plans
Rules:
- One topic per file.
brain/codebase/deploy-gotchas.md, not a mega-file.
- Maintain existing index entrypoints:
brain/index.md, brain/principles.md.
- If you introduce a new top-level category, add an index-style entrypoint for it (links only, no inlined content).
brain/index.md is the root. Every brain file must be reachable from it.- File names: lowercase, hyphenated.
worktree-gotchas.md.
Wikilinks
Format: [[section/file-name]]. Resolution order: same directory, then relative path, then vault root. Heading anchors ([[file#heading]]) are stripped during resolution.
Writing Style
- Bullets over prose. No preamble.
- Plain markdown with
# Title. No Obsidian frontmatter.
- Keep notes under ~50 lines. Split if longer.
After Writing
Do not edit brain/index.md — the auto-index-brain.sh PostToolUse hook regenerates it. Do update the relevant subindex (brain/principles.md, brain/codebase/index.md, brain/plans/index.md) when applicable. Keep subindexes link-only and scannable.
Durability Test
Ask: "Would I include this in a prompt for a different task?"
- Yes -> write to
brain/. It's durable knowledge.
- No, it's plan-specific -> update the plan's docs instead.
- No, it's a skill issue -> update the skill file directly.
- No, it needs follow-up work -> file a todo.
Maintenance
- Delete outdated or subsumed notes.
- Merge overlapping notes before adding new ones.
