PreToolUse

PreToolUse is a hook for Claude Code from bjornjee/agent-dashboard. Its token cost is not measured, scanned C, original, MIT.

A set of checks that run before selected shell commands and can warn or block unsafe actions.

In plain words
What is it for?
Use it to enforce safer branching and pull-request workflows, protect against commands such as deleting data, and require write-enabled delegated tasks.
Why use it?
It helps prevent destructive commands, commits directly to the main branch, unapproved pull requests, and read-only delegation mistakes.

Hook for Claude Code

Written for Claude Code: ${CLAUDE_PLUGIN_ROOT} variable. Also seen: mentions Codex.

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 agent-dashboard plugin — 8 skills, 5 agents, 10 hooks shipped together

One of 10 entries in hooks.json upstream. Installing this one merges just its entry into your config; the other 9 are separate, each on its own page.

Good fit Use it to enforce safer branching and pull-request workflows, protect against commands such as deleting data, and require write-enabled delegated tasks.

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 bjornjee/agent-dashboard
Claude Code
/plugin install agent-dashboard

Made for: Claude Code.

Or install agent-dashboard, the plugin that ships this one along with the rest of its 8 skills, 5 agents, 10 hooks.

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/bjornjee/agent-dashboard/pre-tool-use/github.svg)](https://agentmods.dev/hooks/bjornjee/agent-dashboard/pre-tool-use)
Your own site
<a href="https://agentmods.dev/hooks/bjornjee/agent-dashboard/pre-tool-use"><img src="https://agentmods.dev/badge/hooks/bjornjee/agent-dashboard/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/bjornjee/agent-dashboard/pre-tool-use"><img src="https://agentmods.dev/badge/hooks/bjornjee/agent-dashboard/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 C 1 finding. 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 C, and why

PreToolUse scanned grade C with 1 finding 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 1mo 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.

Recursive force deletehighDestructive command

rm -rf with a variable or a broad path is one typo away from removing the wrong tree.

"description": "Block destructive shell commands (rm -rf, git reset --hard, DROP TABLE, etc.)"
Origin

Copies of this mod

1 near-identical copy found in the catalogue:

adapters/claude-code/hooks/hooks.json · 56 lines

What it actually says

{
  "PreToolUse": [
    {
      "matcher": "Bash",
      "hooks": [
        {
          "type": "command",
          "command": "node \"${CLAUDE_PLUGIN_ROOT}/scripts/hooks/warn-destructive.js\""
        }
      ],
      "description": "Block destructive shell commands (rm -rf, git reset --hard, DROP TABLE, etc.)"
    },
    {
      "matcher": "Bash",
      "hooks": [
        {
          "type": "command",
          "command": "node \"${CLAUDE_PLUGIN_ROOT}/scripts/hooks/block-main-commit.js\""
        }
      ],
      "description": "Block git commit on main/master — require a feature branch"
    },
    {
      "matcher": "Bash",
      "hooks": [
        {
          "type": "command",
          "command": "node \"${CLAUDE_PLUGIN_ROOT}/scripts/hooks/pr-skill-gate.js\""
        }
      ],
      "description": "Block direct gh pr create — require /agent-dashboard:pr"
    },
    {
      "matcher": "Bash",
      "hooks": [
        {
          "type": "command",
          "command": "node \"${CLAUDE_PLUGIN_ROOT}/scripts/hooks/codex-write-gate.js\""
        }
      ],
      "description": "Block codex-companion task without --write (prevents read-only sandbox)"
    },
    {
      "matcher": "*",
      "hooks": [
        {
          "type": "command",
          "command": "node \"${CLAUDE_PLUGIN_ROOT}/scripts/hooks/agent-state-fast.js\"",
          "async": true,
          "timeout": 3
        }
      ],
      "description": "Fast state sync for dashboard (state, permission_mode, current_tool)"
    }
  ]
}
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. 1mo ago First seen · 56 lines scan C cfeeda653d7f

Subscribe to this mod's changes

PreToolUse is a hook published in the GitHub repository bjornjee/agent-dashboard (26 stars, last pushed 3mo ago), licensed MIT. Its token cost is not measured: a hook is shell that never enters the context. A static security scan graded it C with 1 finding (recursive force delete). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.