/project-brain

name: project-brain
description: |
  Triggers (all require explicit user request — do NOT activate just because a brain/ folder exists):
  (1) The user wants to set up project-level memory ("set up project brain", "scaffold project context", "init project brain", "建项目脑").
  (2) The user is in a directory containing brain/ AND explicitly asks to resume / continue / load the project / check status / "what's the state of this project" / "继续这个项目".
  (3) The user signals window switch / context compaction ("switch windows", "context's getting full", "I'll head out", "压缩了", "切窗口") — write a HANDOFF before they leave.
  (4) The user says "update the project brain" / "let's record this" / "更新项目脑" — propose a list with reasons; user approves per item.
  (5) The user mentions multiple parallel workstreams / 多线程项目 / 多任务并行 — enable Multi-workstream Mode (METHODOLOGY §3.5).
  Do NOT auto-activate from casual conversation — explicit user request required. See METHODOLOGY.md.
allowed-tools: ["Read", "Write", "Edit", "Bash", "Glob", "Grep"]

project-brain

A folder structure + collaboration protocol for persistent project context across AI sessions. Use it to scaffold a `brain/` folder in the user's project, resume work from an existing one, or update entries when work happens.

When to invoke this skill

| User signal | Workflow | |---|---| | "set up project brain" / "scaffold project" / "建项目脑" / "init project context" | **Kick-off** — see §1 | | User is in a directory containing `brain/` **AND** explicitly says "load" / "resume" / "what's the status" / "继续这个项目" | **Startup** — see §2 | | User says "switch windows" / "context's getting full" / "I'll head out" / "压缩了" / "切窗口" | **Handoff** — see §3 | | User says "update the project brain" / "let's record this" / "更新项目脑" | **Update** — see §4 |

**Activation boundary** (important): Do **not** activate just because a `brain/` folder exists in the current directory. Casual conversation that happens to occur inside a project does not require this skill — only explicit user requests do. This is intentional: the methodology refuses to auto-monitor or auto-trigger; user judgment decides when to engage.

Core principles (always honored)

• **Tiered trust on `brain/` writes** (v2.6, METHODOLOGY §4.1): `STATUS` / `HANDOFF` / mechanical `MAP` registrations — write directly after the work lands, then **announce what was written in the same reply** (git is the review surface; silent writes are forbidden at every tier). `DECISIONS` / `PROJECT` / structural `MAP` changes — always ask first.
• **Judgment Division**: the user decides "should we record now"; the AI decides "what specifically to record"; the user reviews. Don't push specialized judgments back to the user ("which files do you want me to update?").
• **DECISIONS gentle inquiry**: when something feels decided, ask "does this count as decided?" — don't assert "we decided X."
• **Multi-workstream**: if `brain/` has multiple `STATUS_<workstream>.md` files, don't guess this window's workstream — ask the user.

§1 New project kick-off

When the user wants to scaffold:

1. **Confirm applicability**: multi-module / long-lived / cross-session work? If a one-off script — say "this might be over-engineering for this project" and let the user override. 2. **Confirm single or multi-workstream**: most projects are single-workstream (default). If the project has parallel independent workstreams (dev + ops + outreach kind of project), ask the user to list workstream names. 3. **Run scaffold**: `bash "${CLAUDE_PLUGIN_ROOT}/scripts/scaffold.sh" <user-project-root>` (defaults to all four AI adapters: Claude, Cursor, Copilot, AGENTS.md). Add `--lang zh` if the project will be documented in Chinese — gives Chinese `brain/` templates + Chinese `CLAUDE.md` (other adapters stay English regardless, since they're consumed by AI tools, not humans). 4. **Walk the user through `brain/PROJECT.md`** on day one — fill the one-line definition + "what we explicitly DON'T do." Don't let this drift into the future. 5. **Scan placeholders**: `grep -rn "⚠️ TODO ⚠️" <user-project>/brain/` — go through with the user. Empty fields should be intentional. 6. **First DECISIONS entry**: append "establishing project-brain" with rejected alternatives, so this file is used from day one.

§2 Startup (entering a project that already has `brain/`)

**Single-workstream** (only `STATUS.md`): 1. Read `brain/MAP.md` 2. Read `brain/STATUS.md` 3. If `brain/HANDOFF.md` exists, read it 4. Brief report: project recognized + current progress + last blocker

**Multi-workstream** (multiple `STATUS_<workstream>.md`): 1. Read shared files: `brain/MAP.md` + `brain/PROJECT.md` 2. **Don't guess** — ask: "I see this is a multi-workstream project with [list workstreams]. Which one does this window work on?" 3. After the user answers, read corresponding `brain/STATUS_<workstream>.md` + `brain/HANDOFF_<workstream>.md` 4. Brief report

**Universal discipline**: if `cwd` switches to another project mid-session, re-read the new project's files; if the user switches workstreams in the same window, re-read the new workstream's files. Don't carry over memory.

§3 Handoff (user signaling window switch)

When the user says they're switching windows / context is getting full / heading out:

1. **Archive the existing HANDOFF first** (if one exists):

   git mv brain/HANDOFF.md brain/handoffs/$(date +%Y-%m-%d-%H%M).md

(For multi-workstream: `brain/HANDOFF_<current>.md` → `brain/handoffs/<current>/...`.) 2. **Write a fresh `brain/HANDOFF.md`** capturing:

• Why the window-switch (context limit / break / refocus)
• Current state at this exact moment
• Where the next session should pick up
• **Things still in head not yet written down** — the unique value of HANDOFF (hunches, half-tried approaches, weird debugging observations)

3. Keep it short. If STATUS was just overwritten, HANDOFF can be near-empty.

§4 Update workflow

When the