# Sac Session

> Open or close an isolated second-brain write session (worktree + PR). Use before scanning or materializing architecture when multiple agents share one knowledge remote.

- Skill: `spillwavesolutions/sac-session` (Agent Skill)
- Install (CLI): `npx skillmds@latest add spillwavesolutions/sac-session`
- Raw SKILL.md: https://api.skillmd.com/api/skills/spillwavesolutions/sac-session/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: spillwavesolutions (https://skillmd.com/u/spillwavesolutions)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/spillwavesolutions/sac-session

---


# sac-session

## When

- More than one agent or machine writes the shared second brain
- The current project worktree is not the knowledge repo
- The user asks to isolate writes, open a knowledge PR, or avoid clobbering main

## Open

```bash
python3 "${CLAUDE_PLUGIN_ROOT}/scripts/brain_session.py" open \
  --repo . \
  --bundle knowledge \
  --actor "${SECOND_BRAIN_IDENTITY:?claim an identity first}" \
  --plugin system-architecture-capture \
  --host claude-code
```

Export `SECOND_BRAIN_ROOT` and `BRAIN_SESSION_ID` from the JSON. All writes go to that bundle via `scripts/sac_*.py`.

## Close

```bash
python3 "${CLAUDE_PLUGIN_ROOT}/scripts/brain_session.py" close \
  --repo . \
  --session "${BRAIN_SESSION_ID}"
```

Pushes to whatever remote the checkout already has and opens a PR when `gh` is available. Never force-push. Never invent a remote URL.

## Rules

- Read shared truth from main. Overlay this session only.
- Do not pack other agents' open branches.
- Public examples use fictional **lumenfield-detector** and **northstar-console** only.
- See `docs/ISOLATION.md`.