PreToolUse

PreToolUse is a hook for Claude Code from Hassaan146/forge-mentor. Its token cost is not measured, scanned A, original, MIT.

A set of checks that runs before the agent reads, edits, writes files, or runs shell commands. It uses Python scripts to control changes, safety checks, and command gates.

In plain words
What is it for?
Use it to inspect and control the agent's file operations and Bash commands before they run.
Why use it?
It helps catch unsafe or disallowed actions before the agent makes them. This reduces the chance that a bad file change or shell command goes through unnoticed.

Hook for Claude Code

Written for Claude Code: ${CLAUDE_PLUGIN_ROOT} variable. Also seen: names the NotebookEdit tool.

Runs only inside its plugin — its command needs a path that Claude Code sets for a plugin’s own hooks and for nothing else. Install the plugin, not this.

Part of the forge plugin — 4 skills, 6 commands, 4 agents, 4 hooks, 1 MCP server shipped together

One of 4 entries in hooks.json upstream. Installing this one merges just its entry into your config; the other 3 are separate, each on its own page.

Good fit Use it to inspect and control the agent's file operations and Bash commands before they run.

Compare 6 hooks from other repositories ↓
Install

Getting it into your agent

This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.

Claude Code
/plugin marketplace add Hassaan146/forge-mentor
Claude Code
/plugin install forge

Made for: Claude Code.

Or install forge, the plugin that ships this one along with the rest of its 4 skills, 6 commands, 4 agents, 4 hooks, 1 MCP server.

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/hassaan146/forge-mentor/pre-tool-use/github.svg)](https://agentmods.dev/hooks/hassaan146/forge-mentor/pre-tool-use)
Your own site
<a href="https://agentmods.dev/hooks/hassaan146/forge-mentor/pre-tool-use"><img src="https://agentmods.dev/badge/hooks/hassaan146/forge-mentor/pre-tool-use/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for PreToolUse

Your own site · 80×15
<a href="https://agentmods.dev/hooks/hassaan146/forge-mentor/pre-tool-use"><img src="https://agentmods.dev/badge/hooks/hassaan146/forge-mentor/pre-tool-use.svg" alt="Reviewed on agentmods" width="80" 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. A grade says what 26 rules found in the file — not that it is safe.
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 9d 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.

hooks/hooks.json · 35 lines

What it actually says

{
  "PreToolUse": [
    {
      "matcher": "Write|Edit|NotebookEdit",
      "hooks": [
        {
          "type": "command",
          "command": "python \"${CLAUDE_PLUGIN_ROOT}/scripts/governor.py\"",
          "timeout": 10
        }
      ]
    },
    {
      "matcher": "Read|NotebookRead|Bash",
      "hooks": [
        {
          "type": "command",
          "command": "python \"${CLAUDE_PLUGIN_ROOT}/scripts/safety.py\"",
          "timeout": 10
        }
      ]
    },
    {
      "matcher": "Bash",
      "hooks": [
        {
          "type": "command",
          "command": "python \"${CLAUDE_PLUGIN_ROOT}/scripts/gates.py\"",
          "timeout": 300,
          "_note": "Above gates.TEST_TIMEOUT (240s). If the two matched, this hook could be killed before the script returned its timeout denial — and a gate that dies lets the commit through."
        }
      ]
    }
  ]
}
Same file

What else hooks.json configures

This page is one entry in a file that holds 4. Installing the file brings all of them; each is measured and scanned on its own page.

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. 9d ago First seen · 35 lines scan A 6a0f5726bb6e

Subscribe to this mod's changes

PreToolUse is a hook published in the GitHub repository Hassaan146/forge-mentor (22 stars, last pushed 23d 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. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.