Brain

Invoke as /afk:brain. Use it when a task needs to read or write the persistent brain/ vault directly: adding a principle, recording a codebase gotcha, or grounding work in existing memory.

brain applies a durability test before writing — durable notes become one-topic files, and the PostToolUse hook keeps index.md in sync.

What it does

Brain is the direct read/write interface to the project's persistent Obsidian vault at brain/. Before writing, it applies a durability test: "Would I include this in a prompt for a different task?" Only content that passes is written: durable knowledge such as principles, gotchas, and decisions. Plan-specific notes belong in the plan's docs; skill process fixes go in the skill file directly.

• Reads brain/index.md and the relevant entrypoint before writing; prefers editing existing notes over creating new ones.
• One topic per file, lowercase hyphenated names, bullets over prose after the summary line.
• Every brain file must be reachable from brain/index.md (auto-rebuilt by the PostToolUse hook on writes, so do not hand-edit it).
• Notes stay under ~50 lines; longer content is split into separate files with a linking index.

View the full skill on GitHub