🌳 pi-worktree — Safe Git Worktree Management for Pi

@narumitw/pi-worktree adds one interactive /worktree command for common Git worktree operations and Pi workspace switching.

Pi cannot change its parent process working directory with cd. This extension performs the safe equivalent: it prepares a Pi session whose cwd is the selected worktree and switches to that session, preserving the current conversation when it has already been persisted.

✨ Features

• Shows compact main, linked, current, detached, locked, and prunable state in worktree selectors.
• Creates a new branch worktree or attaches an existing unoccupied local branch.
• Rejects occupied targets and unresolvable symbolic-link ancestors before Git can create a branch.
• Suggests ~/.worktrees/<main-worktree-name>/<branch> by default and lets the user configure the root interactively.
• Optionally switches Pi into a newly created worktree while continuing the current conversation.
• Switches among existing registered worktrees through Pi's public session replacement API.
• Removes unlocked, non-current linked worktrees and preserves their branches.
• Refuses removal when tracked, untracked, manually index-flagged, submodule, or current unreachable detached-commit data may be lost.
• Allows ignored-only data such as node_modules/ after listing it in the destructive confirmation.
• Names recovery-only administrative commits in the destructive confirmation instead of making ordinary rebase/reset history block cleanup forever.
• Always previews stale metadata before pruning it and revalidates the preview after confirmation.
• Runs Git through argv-based subprocess calls, without interpolating user input into shell commands.

📦 Install

pi install npm:@narumitw/pi-worktree

Try without installing permanently:

pi -e npm:@narumitw/pi-worktree

Try this package locally from the repository root:

just try-worktree
# or: pi -e ./extensions/pi-worktree

💬 Usage

Run the command without arguments:

/worktree

Choose one action:

• Add worktree — enter a branch, optional start point, and optional path; confirm creation and optionally switch.
• Switch worktree — select another existing worktree and continue this Pi conversation there.
• Remove worktree — remove a linked worktree without deleting its branch; ignored-only data is listed for explicit confirmation.
• Prune stale metadata — inspect Git's dry-run output, then optionally run the matching prune.
• Configure worktree root — set a machine-local default root or submit a blank value to restore ~/.worktrees.

The standard root menu shows the registered count, current path, effective worktree root, its source, and any settings warning. Escape closes it. /worktree intentionally does not accept text subcommands or expose argument autocomplete. Every change is initiated and confirmed through TUI or RPC dialogs; print and JSON modes reject the command observably. Operation-specific branch/path inputs, worktree identity selectors, preflight previews, and destructive confirmations remain extension-owned because they carry Git safety and commit-aware revalidation.

🌿 Add defaults

For a new branch, the current symbolic branch is the default start point. If Pi is running from detached HEAD, the command requires an explicit commit-ish. Git must resolve the start point to exactly one commit.

The default root is ~/.worktrees, where ~ is Node's platform home directory. Suggestions use the registered main worktree's directory name, not the current linked-worktree cwd:

main worktree: /home/user/workspace/project
branch:        feat/login
root:          /home/user/.worktrees
suggested:     /home/user/.worktrees/project/feat-login

On Windows, the equivalent default is such as C:\Users\Alice\.worktrees. Branch / characters become -. The extension does not add hashes or collision suffixes: if two normalized paths collide or the target already exists, Add stops before Git mutation.

Leave the path input blank to accept the suggestion. A custom absolute path is used directly; a custom relative path is resolved from the current Pi cwd. The target itself must not exist, and its nearest existing ancestor must resolve without a broken or looping symbolic link. Existing registered worktrees are never moved when this default changes.

The MVP does not expose --force, -B, --detach, --orphan, or lock options.

⚙️ Worktree root settings

The machine-local user settings file is:

<getAgentDir()>/pi-worktree.json

For a default Pi installation this is typically ~/.pi/agent/pi-worktree.json. Configure it through Configure worktree root or edit it manually:

{
  "worktreeRoot": "~/worktrees"
}

worktreeRoot accepts ~, a home-prefixed path such as ~/worktrees, or a native-platform absolute path. It does not expand $VAR, %VAR%, or other shell syntax. Empty, relative, NUL-containing, non-string, and invalid paths are rejected. There is no project override or extension-specific environment variable.

A missing worktreeRoot uses ~/.worktrees; the settings file is created only by a successful interactive change. Submitting a blank value in the interactive action removes the override. Within one Pi process, queued saves run in invocation order, reread the latest valid document immediately before merging worktreeRoot, and preserve concurrent unknown-field edits. Settings reload on every session_start, including /reload and workspace replacement; a successful interactive save applies immediately to the next Add flow.

Malformed or invalid settings are warned about but never overwritten, including an invalid edit made while a settings action is open. An initial failure uses ~/.worktrees; a later failure retains the last valid effective root. Interactive configuration remains blocked until the invalid file is fixed manually. Failed publication leaves the prior file and effective runtime root unchanged, and the save queue remains usable after rejection.

🔀 Pi workspace switching

Switching uses Pi's public SessionManager and ctx.switchSession() APIs:

1. The command waits for Pi to become fully idle so the current assistant/tool results are persisted.
2. A linear persisted session is forked into the target worktree. If /tree currently points at an older branch, the documented session entries for that active branch are written to the target instead, so switching cannot jump to a newer serialized leaf.
3. Pi tears down the old cwd-bound runtime and creates the target runtime.
4. The extension reports success only through the fresh replacement-session context.

If the current session is completely empty, the extension creates a valid empty Pi session for the target. If the current session is ephemeral (--no-session), the extension copies its active conversation branch into a persisted target session so the workspace switch does not lose context.

A successfully created Git worktree is never rolled back merely because Pi session switching fails. Re-run /worktree and choose Switch worktree after resolving the reported Pi/session issue.

🛡️ Safety boundaries

• The main worktree and current worktree cannot be removed.
• Locked or stale worktrees cannot be removed through this extension.
• Dirty, untracked, initialized-submodule, and intentional assume-unchanged/skip-worktree index state causes removal to fail closed. Sparse-checkout-managed skip-worktree entries outside the active sparsity rules are allowed when Git's rule checker can confirm them; clear other intentional index flags before removing the worktree.
• Ignored-only files and directories do not block removal. The confirmation lists them, and the extension rechecks the exact ignored inventory before Git deletes the worktree.
• A detached HEAD must be reachable from a local branch, tag, or remote ref before removal or prune.
• Removal and prune inspect reflogs, pseudorefs, per-worktree refs, and FETCH_HEAD. Historical commits reachable only through this administrative recovery state are listed by full OID in the destructive confirmation; approval removes those recovery pointers, so Git may later garbage-collect the commits. Create a branch or tag instead when any listed commit should survive.
• Staged-only administrative index state, a missing attached branch ref, or an unreachable current detached HEAD still blocks prune without an override.
• Removal never deletes a branch and never uses --force.
• Remove invokes only argv-based git worktree remove <path>; production runtime never invokes a shell, rm, rm -rf, or a Node filesystem directory-deletion API for worktrees.
• Prune always runs git worktree prune --dry-run --verbose before confirmation, inspects candidates omitted from porcelain, rechecks the exact preview and recovery-risk set after confirmation, and uses Git's default expiry. Remove likewise rechecks worktree identity, inventory, administrative path, and the approved recovery-risk set before mutation.
• The extension does not commit, push, rebase, repair, move, lock, or unlock worktrees.

Use Git directly when you intentionally need force removal, branch deletion, custom prune expiry, detach/orphan creation, move, repair, lock, or unlock behavior.

Requirements and limits

• Git must be installed and the current Pi cwd must be inside a non-bare Git worktree.
• The command requires a UI-capable Pi mode; print and JSON modes cannot drive its dialogs.
• Project trust and cwd-bound extension/resource loading during a switch remain owned by Pi.
• The extension registers no LLM tool, background watcher, project settings, or statusline item.

📁 Package layout

extensions/pi-worktree/
├── src/
│   ├── index.ts
│   ├── command.ts
│   ├── git.ts
│   ├── session.ts
│   ├── settings.ts
│   └── worktree.ts
├── test/
│   ├── command.test.ts
│   ├── git.integration.test.ts
│   ├── git.test.ts
│   ├── remove-ignored-command.test.ts
│   ├── session.test.ts
│   └── settings.test.ts
├── package.json
├── README.md
├── LICENSE
└── tsconfig.json

🏷️ Keywords

pi-package, pi-extension, git, worktree, workspace, session

📄 License

MIT