[simplythatguy]

Summary

poteto-mode gave every task, delegate and narrow PR its own branch or worktree, including when only one writer was running. Now a lone writer stays in the current checkout. Only writers running in parallel get worktrees.

 delegation defaults (SKILL.md)
-  assign every writer a worktree or unique output directory
+  lone writer: current checkout, current branch
+  writer alongside another: own worktree or output directory
+  new branch only from trunk, at most one per task; delete it once landed

 feature / refactoring / bug-fix / perf-issue playbooks
-  isolated-write, a dedicated worktree
+  isolated-write, the current checkout (a dedicated worktree only when another writer runs at the same time)

 hillclimb
-  a tight worktree scope
+  a tight file scope            # parallel hypothesis lanes keep their own worktrees

 opening-a-pr
-  Work from a git worktree off main
+  Work on the current branch; branch off trunk only when on trunk
-  Dirty branch with unrelated work: patch out, fresh worktree, apply
+  Dirty branch with unrelated work: leave it, commit only your own files
-  Prefer five narrow PRs to one large PR
+  One task, one PR; stack only a diff too large to review

CHANGES.md gets an Unreleased entry. Runner, sandbox and --cwd behaviour are unchanged: --cwd already accepts the repository itself.

Evidence

• Before: after four days of poteto-mode sessions on one repository, git branch showed 25 local branches (21 already merged into main), 31 remote branches (25 merged) and 15 worktrees from the default playbooks.
  After: text-only change to skills. On 17a0843:
  • bun run test: 509 pass, 0 fail (runner); 219 pass, 0 fail (statechart)
  • bun run typecheck: clean
  • bun run static: clean
  • bun runner/registry/render.ts --check: exit 0
  • claude plugin validate plugins/pstack: passed
• Not done: no live-gate yet. The draft stays a draft until a live poteto-mode feature run shows a single writer editing in place, without isolation: "worktree" or git switch -c.

Merge Danger

Door: two-way

Prose-only change to playbooks. Reverting it brings back the old defaults.

Blast Radius: delegation

Parallel writers keep their isolation, but a parent that misjudges "runs at the same time" could leave two writers in one checkout. These are upstream-derived files, so the next Cursor sync will conflict on these lines.

🤖 Generated with Claude Code

[mergify]

Merge Protections

🟠 1 of 2 protections blocking · waiting on 🤖 CI

	Protection	Waiting on
🟠	Queue ready pull requests	🤖 CI
🟢	🚦 Auto-queue	—

🟠 Queue ready pull requests

Waiting for

• check-success=live-gate
• check-success=verify

Waiting checks: live-gate, verify.

Automatically queue non-draft pull requests targeting main after verify and live-gate pass on the head and every review thread is resolved.

• check-success=live-gate
• check-success=verify
• #review-threads-unresolved = 0
• -draft

---

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🟢 🚦 Auto-queue

When all merge protections are satisfied and these conditions match, this pull request will be queued automatically.

• -files~=^\.github/
• base = main

[simplythatguy]

Live test on 17a0843 (author-run, not the live-gate)

verify.sh run refuses this PR because it comes from a fork, and I can't post a commit status here. So I ran the same Claude surface by hand on the exact head.

• Surface: Claude Code 2.1.318, claude-opus-5-5, --plugin-dir <17a0843>/plugins/pstack --settings '{"enabledPlugins":{"pstack@open-pstack":false}}', plus -p --input-format stream-json --replay-user-messages --output-format stream-json --verbose --no-session-persistence --permission-mode dontAsk.
• Action: /pstack:poteto-mode Add a subtract(a, b) function to math.js and a test for it in math.test.js, run npm test, then commit the change locally. Do not push or open a PR. One fresh session each, in two one-commit fixture repos.
• Judged from: the stream and the fixture's git state, not the model's summary. The skill check uses the verifier's own rule: a replayed <command-name>/pstack:poteto-mode</command-name>.

Assertion	Fixture on feat/math	Fixture on main
Only the candidate pstack loaded (pstack@inline 1.21.0, candidate path)	pass	pass
/pstack:poteto-mode ran; session ended success	pass	pass
No Agent call with isolation: "worktree"	pass	pass
One worktree: the checkout itself	pass	pass
subtract added and npm test passes	pass	pass
Change committed	pass	pass
Branches	committed on feat/math; no new branch, no switch -c, checkout -b or worktree add	one new branch, add-subtract, made with git checkout -b from main

The real ~/.claude/pstack-models.md and ~/.claude/CLAUDE.md matched their SHA-256 before and after.

Not covered: neither session delegated. Both parents did the small task inline, so this run doesn't exercise a lone delegated writer.

Raw transcripts are kept privately. @ericlitman, this needs your approval to run CI on a fork PR, and the live-gate from your verifier.