PreToolUse

PreToolUse is a hook for Claude Code from notque/vexjoy-agent. Its token cost is not measured, scanned A, original, MIT.

A set of automatic checks that run before a coding agent reads or changes files or uses other tools.

In plain words
What is it for?
Applying safety, branch, worktree, sensitive-file, formatting, and merge checks before tool calls.
Why use it?
It can catch risky commands, unsafe file access, formatting problems, and edits outside the permitted work area before they cause trouble.

Hook for Claude Code

One of 11 entries in settings.json — they are configured in one file and arrive together.

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/notque/vexjoy-agent/pre-tool-use
Clone the repo
git clone --depth 1 https://github.com/notque/vexjoy-agent

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for PreToolUse

README.md
[![agentmods](https://agentmods.dev/badge/hooks/notque/vexjoy-agent/pre-tool-use.svg)](https://agentmods.dev/hooks/notque/vexjoy-agent/pre-tool-use)
Your own site
<a href="https://agentmods.dev/hooks/notque/vexjoy-agent/pre-tool-use"><img src="https://agentmods.dev/badge/hooks/notque/vexjoy-agent/pre-tool-use.svg" alt="Measured on agentmods" height="20"></a>
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 original No closer match found in the catalogue.
Security

Grade A, and why

PreToolUse 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 3d 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.

.claude/settings.json · 151 lines

How it starts

The opening of the file, as written. The whole thing — 151 lines — stays where its author put it; the contents beside it link to each section on GitHub.

{
  "PreToolUse": [
    {
      "hooks": [
        {
          "type": "command",
          "command": "python3 \"$HOME/.claude/hooks/suggest-compact.py\"",
          "description": "Advisory: suggests /compact when Edit/Write call count reaches threshold (ADR-103)",
          "timeout": 2000
        }
      ]
    },
    {
      "matcher": "Bash|Write|Edit|Read",
      "hooks": [
        {
          "type": "command",
          "command": "python3 \"$HOME/.claude/hooks/pretool-unified-gate.py\"",
          "description": "Unified gate: gitignore-bypass, git-submission, dangerous-command, creation-gate, sensitive-file (ADR-068). Read gets a warn-only sensitive-file check.",
          "timeout": 3000
        }
      ]
    },
    {
      "matcher": "Write|Edit|MultiEdit|NotebookEdit",
      "hooks": [
        {
          "type": "command",
          "command": "python3 \"$HOME/.claude/hooks/pretool-worktree-edit-guard.py\"",
          "description": "Worktree edit guard: blocks worktree-isolated agents from editing main-repo files outside their worktree (ADR worktree-edit-guard)",
          "timeout": 3000
        }
      ]
    },
    {
      "matcher": "Bash",
      "hooks": [
        {
          "type": "command",
          "command": "python3 \"$HOME/.claude/hooks/pretool-branch-safety.py\"",
          "description": "Branch safety: blocks git commit on main/master, forces feature branches",
          "timeout": 3000
        },
        {
          "type": "command",
          "command": "python3 \"$HOME/.claude/hooks/ci-merge-gate.py\"",
          "description": "Gate: block merge to main/master when CI checks are red",
          "timeout": 30000
        },
        {
          "type": "command",
          "command": "python3 \"$HOME/.claude/hooks/pretool-ruff-format-gate.py\"",
          "description": "Ruff format gate: blocks git push when ruff format --check finds violations (Python projects with pyproject.toml only)",
          "timeout": 5000
        },
       

Read the full file on GitHub · 151 lines

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. 3d ago First seen · 151 lines scan A 302cf3182d36

Subscribe to this mod's changes

PreToolUse is a hook published in the GitHub repository notque/vexjoy-agent (419 stars, last pushed today), 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. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.