Underscore Brain wraps your markdown vault in an agent runtime and a keyboard-first desktop. Chat, an approval inbox, notes, daily orchestration — one window, summoned in under 100ms. The same vault still drives from Claude Code and Codex. Two front-ends, one system of record.
Not everything at once — the highest-frequency surfaces first, each a sandboxed view over a typed bridge. Switch between them in under 50 milliseconds, state preserved.
The morning ritual, automated to the edge of consent: it reads, it reasons, it proposes — and stops. Nothing runs until you approve. On approval it emits two artifacts you paste straight into Claude Code.
claude -p --permission-mode plan over vault + index.→# paste at the brain root Impersonate a world-class operator. Create 50-Initiatives/domendor-q3/, drop research, write README-domendor-q3. Context: @50-Initiatives/domendor.md Ask questions, then on approval — build.
# run inside the initiative repo System: sequential rounds of foreground Opus agents + a validate-and-heal round. Attached: README-domendor-q3.md Honor the vault contract. Write only to _BrainOS/_review/ — the human promotes.
_review/; promotion copies them into the vault.Agents write only to a staging folder. You promote or reject — there is no canonical mutation, no data loss, without an explicit decision. The approval gate sits outside the sandbox; a sandbox escape can't disable it.
notify · question · review — one flag-driven renderer, three modes, zero branches.
Chat, retrieval, notes, and the inbox all work offline against a local model and a local index. Cloud models are the only network-dependent surface — and each one is gated, sandboxed, and deny-all by default.
Claude writes. You curate. The agents stay ambient, the gate stays yours, and the vault stays exactly as true as you let it be.