Use it to configure the Claude Code pre-tool event and invoke the project’s .claude/hooks/pre_tool_use.py script.

It lets the project check or control tool use before commands run, applying the repository’s pre-tool rules automatically instead of relying on manual checks.

How nodnarbnitram/claude-code-extensions configures Claude Code

claude-code-extensions: Hook for Claude Code

.claude/settings.json

PreToolUse is a hook for Claude Code from nodnarbnitram/claude-code-extensions. Its token cost is not measured, scanned A, original, MIT.

A pre-tool hook configuration that runs a Python script before the coding agent uses a tool. A hook is an automatic action triggered by a particular event.

In plain words

What is it for?: Use it to configure the Claude Code pre-tool event and invoke the project’s .claude/hooks/pre_tool_use.py script.
Why use it?: It lets the project check or control tool use before commands run, applying the repository’s pre-tool rules automatically instead of relying on manual checks.

Written for Claude Code: ${CLAUDE_PLUGIN_ROOT variable.

This is nodnarbnitram/claude-code-extensions's own configuration. It tells Claude Code how to work on claude-code-extensions itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything claude-code-extensions configures →

Runs only inside a plugin — its command needs a path that Claude Code sets for a plugin’s own hooks and for nothing else, and the catalogue could not identify which plugin ships it.

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

Reuse

Borrowing it

Nothing to install: this file belongs to nodnarbnitram/claude-code-extensions. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/nodnarbnitram/claude-code-extensions/main/.claude/settings.json

Clone the repo

git clone --depth 1 https://github.com/nodnarbnitram/claude-code-extensions

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.

README.md

[![agentmods](https://agentmods.dev/badge/hooks/nodnarbnitram/claude-code-extensions/pre-tool-use/github.svg)](https://agentmods.dev/hooks/nodnarbnitram/claude-code-extensions/pre-tool-use)

Your own site

<a href="https://agentmods.dev/hooks/nodnarbnitram/claude-code-extensions/pre-tool-use"><img src="https://agentmods.dev/badge/hooks/nodnarbnitram/claude-code-extensions/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/nodnarbnitram/claude-code-extensions/pre-tool-use"><img src="https://agentmods.dev/badge/hooks/nodnarbnitram/claude-code-extensions/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 2mo 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 · 13 lines

What it actually says

{
  "PreToolUse": [
    {
      "matcher": "",
      "hooks": [
        {
          "type": "command",
          "command": "uv run \"${CLAUDE_PLUGIN_ROOT:-$CLAUDE_PROJECT_DIR}\"/.claude/hooks/pre_tool_use.py"
        }
      ]
    }
  ]
}

Same file

What else `settings.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.

2mo ago First seen · 13 lines scan A 7b0a8c63e522

Subscribe to this mod's changes

PreToolUse is a hook published in the GitHub repository nodnarbnitram/claude-code-extensions (17 stars, last pushed 6mo 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.

PreToolUse next to 6 hooks from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
PreToolUsenodnarbnitram/claude-code-extensions	Hook	17	6mo 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