worktree-setup

name	worktree-setup
description	Bootstrap and maintain Claude Code worktree auto-setup for a repo. Interviews the codebase for what a fresh `claude --worktree` actually needs — gitignored files, install/build steps, per-worktree ports, shared caches — then generates, wires, and smoke-tests the right `.worktreeinclude` + hook. Re-run to update the config when the repo changes. User-triggered via `/quality:worktree-setup [setup|update|check]`.
argument-hint	[setup | update | check]
disable-model-invocation	true

quality-worktree-setup

When you start a session with claude --worktree, the new worktree is missing every gitignored file (.env, local config, certs) and has run no install or build step — so it often can't run. This skill makes a repo set itself up automatically on every new worktree. It does that by interviewing the codebase for what a fresh worktree needs, then generating and verifying the right files and hooks. It is not a drop-in template: the value is the discovery + the human-in-the-loop confirmation of what belongs in this repo.

It has three modes:

• setup — first-time bootstrap. Discover → confirm → generate → verify. Once.
• update — re-discover, diff against the existing managed config, propose a patch. Run whenever the repo's tooling or secrets change.
• check — verify the current config (optionally a live smoke test) without changing anything.

When to use

User-triggered only. Activate on:

• /quality:worktree-setup — auto-pick: update if a managed config exists, setup otherwise.
• /quality:worktree-setup setup — force the bootstrap interview.
• /quality:worktree-setup update — re-discover and diff against existing config.
• /quality:worktree-setup check — verify only; never writes.

Do not self-activate on related phrasing ("set up worktrees", "fix my .env"). Surface the slash command and let the user decide.

Read this first

Read references/approaches.md before choosing an approach or writing any file. It carries the verified hook contracts, the SessionStart-vs-WorktreeCreate tradeoff table, the port/symlink snippets, and the non-negotiable correctness details (linked-worktree guard, run-once marker, stdout discipline). Do not rely on memory for hook event names or contracts — they're in that file.

Mode dispatch — run this first

Detect whether this skill already manages worktree setup here:

root=$(git rev-parse --show-toplevel 2>/dev/null) || { echo "not a git repo"; }
managed=0
for f in "$root/.claude/hooks/worktree-init.sh" "$root/.claude/hooks/worktree-create.sh"; do
  [ -f "$f" ] && grep -q "managed by quality-worktree-setup" "$f" && managed=1
done
echo "root=$root managed=$managed"

• No argument + managed=0 → setup.
• No argument + managed=1 → update.
• Explicit setup / update / check → that mode. (update/check with managed=0: tell the user nothing is configured yet and offer to run setup.)

If git rev-parse fails, the repo isn't git. The default git creation path won't work, so only the WorktreeCreate (non-git) path is viable — say so and confirm the user still wants to proceed.

---

Phase D — Discover (the interview)

Inspect the repo and build a worktree spec across four buckets. Investigate, then present findings and let the user edit before generating anything. Never print secret values — only filenames.

1. Gitignored-but-needed files

A fresh worktree starts without these. Find what's present and untracked:

git -C "$root" status --ignored --porcelain | grep '^!!' | sed 's/^!! //'

Focus on runtime-required, non-regenerable files — .env*, config/secrets*, *.pem / certs, service-account JSONs, .npmrc/.netrc with tokens, local SQLite DBs. Exclude regenerable junk (node_modules, .venv, dist, __pycache__, caches) — those come from installs or symlinks, not copies. Cross-reference .env.example / .env.sample to learn which env files the repo expects. Present the candidate list and let the user add/remove.

2. Install / build steps

Detect the toolchain from manifests + lockfiles, and prefer an existing setup target over inventing commands:

• Check for a ready-made entry point first: a setup/bootstrap/dev:setup script in package.json, a Makefile/Justfile target, bin/setup, script/bootstrap. If one exists, propose reusing it.
• Otherwise infer per ecosystem: uv.lock→uv sync; poetry.lock→poetry install; requirements.txt→pip install -r; package.json + lockfile → the matching bun/pnpm/npm ci/yarn; Cargo.toml→cargo build; go.mod→go mod download; Gemfile→bundle install; composer.json→ composer install.
• Walk monorepo sub-packages (e.g. ui/package.json, workspaces) — each may need its own install.
• Guard each command with a tool/file check (command -v uv >/dev/null && [ -f uv.lock ] && …) so a missing tool degrades gracefully.

3. Per-worktree collision risks

Parallel worktrees clash on fixed resources. Grep for hard-coded dev-server ports (PORT=, listen(3000), vite/next/rails defaults), fixed local DB/Redis names, and fixed container/compose names. For each clashing resource, propose the deterministic port-hash snippet from references/approaches.md (stable per branch, unique across worktrees), and ask where the value is read (which env file / config) so the script writes it correctly.

4. Shared / heavy artifacts

Identify large regenerable trees (node_modules, model files, build caches) that could be symlinked from the main checkout instead of reinstalled. Symlinking is opt-in and has real tradeoffs (a worktree install mutates the main checkout; breaks with diverging lockfiles or native deps) — present it with the caveat from references/approaches.md and default to a clean reinstall unless the user accepts the risk. When they want speed without the risk, prefer symlinking a global package store + a fast linking install.

At the end of Phase D, show the assembled spec (files / installs / ports / caches) and get explicit confirmation. This confirmation is the point of the skill — do not skip it.

---

Phase C — Choose the approach

Apply the decision logic from references/approaches.md:

• Files only, no installs → .worktreeinclude alone.
• Files + installs/ports/symlinks → DEFAULT: .worktreeinclude (files) + SessionStart init script (commands). Future-proof, never touches git, forgiving on failure. Ports and symlinks live in the init script.
• Escalate to WorktreeCreate only when (a) setup must finish before the TUI appears, or (b) the repo is non-git. Present this as an explicit opt-in with its tradeoffs (you own git creation, can drift, strict stdout contract, failure blocks worktree creation, .worktreeinclude bypassed) — never pick it silently.

State which approach you chose and why before generating.

---

Phase G — Generate

Copy the matching template from assets/ and fill its --- BEGIN/END generated: <id> --- regions with the confirmed spec. Keep the managed by quality-worktree-setup header — update mode keys off it. Concretely:

1. Files → write/extend .worktreeinclude from assets/worktreeinclude.example with the confirmed gitignored files. (Under the WorktreeCreate path, .worktreeinclude is bypassed — put the cp lines in the hook's secrets region instead.)
2. Hook script → copy assets/worktree-init.sh (SessionStart) or assets/worktree-create.sh (WorktreeCreate) to .claude/hooks/, fill the generated regions (installs, ports, caches, and secrets when applicable), then chmod +x.
3. Wire the hook → merge the matching block from assets/settings.snippet.json into .claude/settings.json. Merge, never overwrite — read existing JSON, add to the relevant hooks array, preserve everything else. Validate the result parses (jq . < file).
4. gitignore → ensure .claude/worktrees/ is in .gitignore (add if missing).

Show a diff/summary of every file touched.

---

Phase V — Verify

Confirm the config actually works. Default to the live smoke test; offer the static fallback when installs would be slow or the user declines.

Live smoke test (uses -p to skip the trust dialog; see references/approaches.md):

name="qws-smoke-$$"
claude -p --worktree "$name" "exit" >/dev/null 2>&1 || true
dir="$root/.claude/worktrees/$name"
# Assert: expected gitignored files landed, install artifacts exist
# (node_modules / .venv / target …), the .claude-worktree-ready marker was
# written (SessionStart path), and any port file is present.
git -C "$root" worktree remove --force "$dir" 2>/dev/null || true
git -C "$root" branch -D "worktree-$name" 2>/dev/null || true

Always tear the throwaway worktree + branch down afterward (-p worktrees are never auto-cleaned). Report exactly what was asserted and what passed/failed.

Static fallback: bash -n and shellcheck the hook script(s), and confirm .claude/settings.json parses with jq. Say that you ran the static check instead of a live run, and why.

---

Update mode

1. Re-run Phase D against the current repo → a fresh spec.
2. Read the existing managed files; diff the fresh spec against the --- generated: <id> --- regions only.
3. Present the delta in plain terms ("repo added a pnpm workspace and a STRIPE_KEY env var → add pnpm install to installs and .env to .worktreeinclude; the vite port moved → update the port region").
4. On approval, rewrite only the affected generated regions — never touch hand edits outside them or unrelated keys in .claude/settings.json.
5. Re-run Phase V.

If the repo's needs now cross an escalation trigger (e.g. setup must precede the TUI), say so and offer to migrate SessionStart → WorktreeCreate.

Check mode

Run Phase V against the existing config and report. Never writes. If managed=0, say nothing is configured and offer setup.

Guardrails

• Never print secret values. Reference secret files by name only; never cat .env or copy its contents into your output. (The repo's .env guard may block reads outright — respect it.)
• Merge, don't clobber .claude/settings.json and .gitignore.
• Only rewrite managed regions in update mode.
• Don't commit unless the user asks. When you do, the hook scripts + .worktreeinclude + .gitignore + .claude/settings.json belong in the commit; .claude/worktrees/ stays ignored.
• The hook runs setup commands on every new worktree — keep them idempotent and guarded, and call out anything slow or destructive before generating it.

Output

Close with a short summary:

• Mode run and the approach chosen (+ why).
• Files created/changed (paths).
• What the spec covers (files / installs / ports / caches).
• Verification result (live smoke test or static check, pass/fail).
• How to use it: claude --worktree <name>, and /quality:worktree-setup update when the repo's tooling changes.