Wt Switch Create

Arguments: $ARGUMENTS. Grammar: [<branch>] [<repo>] [-- <task>].

• branch — optional; the branch name for the new worktree. When omitted, pick one (step 1 below).
• repo — optional path; create the worktree in this repo instead of the session's current one.
• task — optional; what to do inside the new worktree. No task means enter the worktree and wait.

Tokens before the -- are the branch and/or repo: a path-shaped token (starting with /, ~, ./, or ../) is the repo; any other token is the branch (docs is a branch name, never the docs/ directory). More than one branch-shaped token before a -- doesn't fit the grammar — ask. Without a --, judge where the task starts: leading tokens that read as a branch name (fix-auth) or a repo path are consumed as such, and the rest is the task; otherwise the whole input is the task (fix the parser bug has no branch-shaped lead — all task).

/wt-switch-create my-feature -- fix the parser bug
/wt-switch-create -- fix the parser bug
/wt-switch-create my-feature ~/workspace/other-repo -- fix the parser bug
/wt-switch-create my-feature

What to do

Creating the worktree comes first on every invocation, before any other work. The invocation is itself the explicit request to create it; a research or read-only task gets one all the same.

<!-- Maintainers: rationale.md (same directory) covers the harness rules and
design choices behind this — read it before re-adding guards or routes. -->

1. Pick the branch name if none was given: short, from the task and consistent with existing worktree names, or, mid-session, from the work being moved; with nothing to derive from, ask.

2. With no repo argument, create and enter in one call: EnterWorktree({name: "<branch>"}). Worktrunk's WorktreeCreate hook runs wt switch --create, so the result is an ordinary wt worktree in the default layout, and the user sees no confirmation prompt. On success, do the task (or, with no task text, confirm it's ready and wait).

   Mid-session, carry uncommitted work across: git stash push -u before the EnterWorktree call, then git stash pop after — the call re-roots the session into the new worktree, and the stash is shared across worktrees.

3. Otherwise create it with wt and enter by path. Two cases reach here: a repo argument, which step 2 can't target, and a failed step 2, whose error says which — ✗ Branch <branch> already exists, or Already in a worktree session. Create with a Bash call (omit -C <repo> for this repo):

   wt -C <repo> switch --create <branch> --no-cd --format=json

   Stdout is JSON whose path field is the worktree's absolute path (status lines go to stderr). On Branch <branch> already exists: if the user named the branch, rerun without --create (it enters the branch, creating its worktree if missing); if step 1 picked the name, pick another and rerun. Any other failure (not a git repo, invalid name): report it and stop.

   Then call EnterWorktree({path: "<path from the JSON>"}).

   • Accepted → the session is re-rooted in the worktree. Do the task (or, with no task text, confirm it's ready and wait).
   • Tool error — the tool ran and returned an error (Cannot enter worktree: …) → graceful; nothing moved, and one recovery covers them all. Common causes: the cwd resolves to no git repo (e.g. a non-git parent like ~/workspace that only holds repos, as in a background job) or to a different repo than the target; or the session is already rooted in a worktree (or is a pinned agent), which limits entry to the current repo's .claude/worktrees/ and excludes even a same-repo wt sibling. The recovery test is whether you can cd into the worktree, which works when it's inside an allowed directory. So cd <path> and read the result:
     • no Shell cwd was reset notice → it stuck; the worktree is reachable. Work there, but a bare cd is not a tracked re-root, so the cwd can revert to the session's launch worktree across turns (and in spawned subagents); pin commands with git -C <path> / wt -C <path> rather than trusting the cd to persist.
     • Shell cwd was reset → not reachable. Stop and ask the user to make it reachable: add the repo, or a parent like ~/workspace, to permissions.additionalDirectories (durable, every session), or run /add-dir <path> (this session). Then continue. Don't grind through absolute paths with cd resetting on every command.
   • Denied — the call itself was refused, with no tool error → however the denial is worded, it is the user's answer to the confirmation Claude Code shows for entering a worktree outside .claude/worktrees/, unless there was no user to ask (the denial says the session couldn't prompt), which decides nothing — take the recovery above. On the user's answer: the worktree wt just created still exists; only the entry didn't happen. Report its path and ask how to proceed, since reaching it through cd would override that answer.