second-brain

A second brain is the durable, source-backed memory for an agent or founder: a folder of plain Markdown notes that opens in Obsidian as an ordinary vault and reads as a clean knowledge base. This skill unifies four capabilities under one roof: capture notes fast, retrieve connected context, compile a vault from raw sources, and optionally maintain it autonomously. Two rules dominate the whole skill: never invent a fact a source does not support, and never ship a copied secret.

Every vault mutation delegates to a script in scripts/. The scripts keep filenames collision-free and writes atomic, and the deterministic validators own every verdict. The vault root resolves itself: vault.sh reads the configured path from skill-config, an explicit $VAULT overrides it, and ./vault is the last-resort fallback. Never hardcode an absolute path.

The depth bar is code-review: judge the vault against what it must deliver (fast recall of connected, source-backed context) and treat per-note tidiness as the smaller test. The determinism doctrine is the foundation.