[BUG] Claude Desktop's worktree creation flow does not fire the WorktreeCreate hook

What's Wrong?

When Claude Desktop creates a git worktree (e.g. via the in-app "new worktree" / cowork flow), the WorktreeCreate hook configured in ~/.claude/settings.json is not invoked. The Desktop app instead creates the worktree directly under <repo>/.claude/worktrees/<name> and records it in ~/Library/Application Support/Claude/git-worktrees.json, bypassing the user's hook entirely.

The same hook fires correctly when invoking claude --worktree <name> from the CLI, so the hook itself and the settings file are wired up correctly — Desktop just doesn't call into the hook dispatch path for this event.

This makes the documented WorktreeCreate override mechanism (https://code.claude.com/docs/en/hooks) ineffective for Desktop users who want worktrees in a non-default location (e.g. a sibling directory <repo>-worktrees/<name> instead of <repo>/.claude/worktrees/<name>).

What Should Happen?

When Desktop creates a worktree, it should dispatch the WorktreeCreate hook the same way the CLI does:

1. Send the JSON payload (cwd, name, hook_event_name, …) to the hook command on stdin.
2. Use the path the hook prints on stdout as the worktree location.
3. Fail worktree creation (with the hook's stderr surfaced) if the hook exits non-zero.

The Desktop's internal git-worktrees.json registry should record whatever path the hook returned, not a hard-coded .claude/worktrees/<name>.

Error Messages/Logs

No error — the hook is silently skipped. /tmp/claude-worktree-create.log (a debug cat in the hook script) gets a new entry on every CLI --worktree invocation but never on a Desktop-initiated worktree.

~/Library/Application Support/Claude/git-worktrees.json shows recent Desktop-created worktrees still under /Users/<me>/projects/<repo>/.claude/worktrees/<name> despite the hook being active.

Steps to Reproduce

1. Add a WorktreeCreate hook to ~/.claude/settings.json:

   {
     "hooks": {
       "WorktreeCreate": [{
         "hooks": [{
           "type": "command",
           "command": "~/.claude/hooks/worktree-create.sh"
         }]
       }]
     }
   }

2. Create ~/.claude/hooks/worktree-create.sh (chmod +x):

   #!/usr/bin/env bash
   set -euo pipefail
   input=$(cat)
   { echo "=== $(date -u +%FT%TZ) ==="; echo "$input"; echo; } >> /tmp/claude-worktree-create.log
   cwd=$(jq -r '.cwd' <<<"$input")
   name=$(jq -r '.name' <<<"$input")
   parent=$(dirname "$cwd"); base=$(basename "$cwd")
   target="$parent/${base}-worktrees/$name"
   mkdir -p "$parent/${base}-worktrees"
   git -C "$cwd" worktree add "$target" >&2
   echo "$target"

3. From the CLI: cd <repo> && claude --worktree probe-cli → Hook fires; worktree appears at <parent>/<repo>-worktrees/probe-cli. /tmp/claude-worktree-create.log gets a new entry. ✅
4. Fully quit Claude Desktop (⌘Q) and relaunch to clear any settings cache.
5. In Desktop: start a new Claude Code session for a project, then enable the "Worktree" toggle for that session. → Worktree appears at <repo>/.claude/worktrees/<generated-name>. /tmp/claude-worktree-create.log is not updated. ❌
6. Inspect ~/Library/Application Support/Claude/git-worktrees.json — the Desktop-created entry's path field points inside .claude/worktrees/, confirming the hook was bypassed.

Related Issues

• #36205 — EnterWorktree tool ignores WorktreeCreate/WorktreeRemove hooks (similar bypass for the agent-tool path)
• #46664 — Plugin-registered WorktreeCreate hooks never dispatched (different scope; both point at the dispatch table being incomplete)
• #42336 — PostToolUse hooks not triggering in Desktop App (closed, but suggests hook plumbing has had gaps before)

Environment

• Claude Desktop: 1.6259.1 (5095e7), build 2026-05-06T03:26:09Z, macOS
• Claude Code CLI: 2.1.117
• macOS: 26.4.1
• Hook configured at user scope in ~/.claude/settings.json