WorktreeCreate

A hook that runs a shell check whenever a Git worktree is created. A worktree is an additional working folder connected to the same Git repository.

In plain words
What is it for?
Use it in projects that use Claude Code Harness to validate its installation during worktree creation. If the harness cannot be found, the check reports that and skips the hook.
Why use it?
It checks that the Claude Code Harness installation is available and valid when a new worktree starts, helping catch missing setup early.

Hook

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add hooks/chachamaru127/claude-code-harness/worktree-create
Clone the repo
git clone --depth 1 https://github.com/Chachamaru127/claude-code-harness
Per session not measured What this adds to a session before it is invoked.
When invoked not measured Not applicable: nothing here is loaded into a session.
Security scan A 0 findings. Scan, not verified.
Origin 92% copy Near-identical to another mod in the catalogue.
Security

Grade A, and why

WorktreeCreate scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the commands this hook runs, not an audit. A hook is shell that executes on your machine at the event it names, which is why every command in it is printed with what was found.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

92% identical to PreToolUse — 46 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

hooks/hooks.json · 13 lines

What it actually says

{
  "WorktreeCreate": [
    {
      "hooks": [
        {
          "type": "command",
          "command": "/bin/bash -c 'valid_root(){ local r=\"${1:-}\"; [ -n \"$r\" ] && [ -x \"$r/bin/harness\" ] && [ -f \"$r/.claude-plugin/plugin.json\" ] && /usr/bin/grep -q \"\\\"name\\\"[[:space:]]*:[[:space:]]*\\\"claude-code-harness\\\"\" \"$r/.claude-plugin/plugin.json\"; }; root=\"${CLAUDE_PLUGIN_ROOT:-}\"; if ! valid_root \"$root\"; then root=\"\"; for c in \"${CLAUDE_PROJECT_DIR:-}\" \"$PWD\" \"$HOME/.claude/plugins/marketplaces/claude-code-harness-marketplace\" \"$HOME/.claude/plugins/cache/claude-code-harness-marketplace/claude-code-harness/\"*; do if valid_root \"$c\"; then root=\"$c\"; break; fi; done; fi; if ! valid_root \"$root\"; then echo \"[claude-code-harness] plugin root not found; hook skipped\" >&2; exit 0; fi; exec \"$root/bin/harness\" \"$@\"' _ hook worktree-create",
          "timeout": 10
        }
      ]
    }
  ]
}
Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 13 lines scan A 937ffd3b7e3f

Subscribe to this mod's changes

WorktreeCreate is a hook published in the GitHub repository Chachamaru127/claude-code-harness (3,079 stars, last pushed 2d ago), licensed MIT. Its token cost is not measured: a hook is shell that never enters the context. A static security scan graded it A with 0 findings. It is 92% identical to PreToolUse, differing in 46 lines, and is treated as a copy.