They can catch unsafe or out-of-scope actions before they happen. They also enforce project rules around branches, worktrees, and available tools.

PreToolUse — Hook for Claude Code by Jerry0022/dotclaude

PreToolUse

PreToolUse is a hook for Claude Code from Jerry0022/dotclaude. Its token cost is not measured, scanned A, original, MIT.

A group of automatic checks that run before the coding agent reads files, runs commands, edits code, or calls certain integrations. These checks inspect things such as token use, branch status, plugin scope, and service health.

In plain words

What is it for?: They help guard terminal commands, file changes, plugin access, branch selection, worktree separation, and connections to external services.
Why use it?: They can catch unsafe or out-of-scope actions before they happen. They also enforce project rules around branches, worktrees, and available tools.

Written for Claude Code: ${CLAUDE_PLUGIN_ROOT} variable.

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 devops plugin — 18 skills, 12 agents, 9 hooks, 1 MCP server shipped together

One of 9 entries in hooks.json upstream. Installing this one merges just its entry into your config; the other 8 are separate, each on its own page.

Good fit They help guard terminal commands, file changes, plugin access, branch selection, worktree separation, and connections to external services.

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 Jerry0022/dotclaude

Claude Code

/plugin install devops

Made for: Claude Code.

Or install devops, the plugin that ships this one along with the rest of its 18 skills, 12 agents, 9 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.

README.md

[![agentmods](https://agentmods.dev/badge/hooks/jerry0022/dotclaude/pre-tool-use/github.svg)](https://agentmods.dev/hooks/jerry0022/dotclaude/pre-tool-use)

Your own site

<a href="https://agentmods.dev/hooks/jerry0022/dotclaude/pre-tool-use"><img src="https://agentmods.dev/badge/hooks/jerry0022/dotclaude/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.

Your own site · 80×15

<a href="https://agentmods.dev/hooks/jerry0022/dotclaude/pre-tool-use"><img src="https://agentmods.dev/badge/hooks/jerry0022/dotclaude/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 11d 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.

plugins/devops/hooks/hooks.json · 13 lines

What it actually says

{
  "PreToolUse": [
    {
      "hooks": [
        {
          "type": "command",
          "command": "node \"${CLAUDE_PLUGIN_ROOT}/hooks/dispatch/dispatch.js\" PreToolUse",
          "timeout": 65
        }
      ]
    }
  ]
}

Same file

What else `hooks.json` configures

This page is one entry in a file that holds 9. 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.

11d ago Changed · -156 lines 65c8d0f7c481
12d ago Changed · +10 lines b7d1828a0be3
15d ago Changed · +4 lines 1ecc2491fb1d
16d ago Changed 149b43e04ca4
28d ago Changed · +10 lines 7f0322d9645e
1mo ago Changed · +19 lines c73e6435ab6e
1mo ago Changed · +10 lines 27bc1ea96909
1mo ago Changed · +13 lines da74ae9ff1d2
1mo ago Changed · +19 lines 99a700af8506
1mo ago First seen · 84 lines scan A d2090d671aa2

Subscribe to this mod's changes

PreToolUse is a hook published in the GitHub repository Jerry0022/dotclaude (6 stars, last pushed 11d 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 2026-08-31.

PreToolUse next to 6 hooks from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
PreToolUseJerry0022/dotclaude	Hook	6	11d ago	MIT	A	—	Claude Code
PostToolUsesupabase/supabase	Hook	115k	yesterday	Apache-2.0	A	—	Claude Code
SessionStartsupabase/supabase	Hook	115k	yesterday	Apache-2.0	A	—	Claude Code
SessionStartgoogle-gemini/gemini-cli	Hook	109k	yesterday	Apache-2.0	A	—	Claude Code
PreToolUseapache/superset	Hook	75k	yesterday	Apache-2.0	A	—	Claude Code
PreToolUseanthropics/claude-cookbooks	Hook	54k	2d ago	MIT	A	—	Claude Code
PostToolUseanthropics/claude-plugins-official	Hook	46k	yesterday	Apache-2.0	A	—	Claude Code