PreToolUse

PreToolUse is a hook for Claude Code from IsaiaScope/ai. Its token cost is not measured, scanned A, a copy of PreToolUse, MIT.

A pre-action check that runs before Bash, Read, or Glob tool calls. Bash runs shell commands, Read opens files, and Glob searches for matching paths.

In plain words
What is it for?
Use it to steer code exploration toward graphify's focused queries and away from unnecessary raw-file searches.
Why use it?
It can add project guidance before the agent searches or reads source code, helping it use a generated knowledge graph when one is available.

Hook for Claude Code

One of 2 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/isaiascope/ai/pre-tool-use
Clone the repo
git clone --depth 1 https://github.com/IsaiaScope/ai

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/isaiascope/ai/pre-tool-use.svg)](https://agentmods.dev/hooks/isaiascope/ai/pre-tool-use)
Your own site
<a href="https://agentmods.dev/hooks/isaiascope/ai/pre-tool-use"><img src="https://agentmods.dev/badge/hooks/isaiascope/ai/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 100% copy Near-identical to another mod 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 4d 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.

Origin

This is a copy

100% identical to PreToolUse — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.claude/settings.json · 22 lines

What it actually says

{
  "PreToolUse": [
    {
      "matcher": "Bash",
      "hooks": [
        {
          "type": "command",
          "command": "CMD=$(python3 -c \"import json,sys; d=json.load(sys.stdin); print(d.get('tool_input',d).get('command',''))\" 2>/dev/null || true); case \"$CMD\" in *grep*|*rg\\ *|*ripgrep*|*find\\ *|*fd\\ *|*ack\\ *|*ag\\ *)   [ -f graphify-out/graph.json ] &&   echo '{\"hookSpecificOutput\":{\"hookEventName\":\"PreToolUse\",\"additionalContext\":\"graphify: knowledge graph at graphify-out/. For focused questions, run `graphify query \\\"<question>\\\"` (scoped subgraph, usually much smaller than GRAPH_REPORT.md) instead of grepping raw files. Read GRAPH_REPORT.md only for broad architecture context.\"}}'   || true ;; esac"
        }
      ]
    },
    {
      "matcher": "Read|Glob",
      "hooks": [
        {
          "type": "command",
          "command": "HIT=$(python3 -c \"import json,sys;d=json.load(sys.stdin);t=d.get('tool_input',d);s=(str(t.get('file_path') or '')+' '+str(t.get('pattern') or '')+' '+str(t.get('path') or '')).lower().replace(chr(92),'/');exts=('.py','.js','.ts','.tsx','.jsx','.go','.rs','.java','.rb','.c','.h','.cpp','.hpp','.cc','.cs','.kt','.swift','.php','.scala','.lua','.sh','.md','.rst','.txt','.mdx');sys.stdout.write('1' if 'graphify-out/' not in s and any(e in s for e in exts) else '')\" 2>/dev/null || true); if [ \"$HIT\" = 1 ] && [ -f graphify-out/graph.json ]; then echo '{\"hookSpecificOutput\":{\"hookEventName\":\"PreToolUse\",\"additionalContext\":\"graphify: knowledge graph at graphify-out/. For codebase questions, run `graphify query \\\"<question>\\\"` (scoped subgraph, usually much smaller than reading files one by one), `graphify explain \\\"<concept>\\\"`, or `graphify path \\\"<A>\\\" \\\"<B>\\\"`, instead of reading source files to answer. Read raw files to modify or debug specific code, or when the graph lacks the detail.\"}}'; fi || true"
        }
      ]
    }
  ]
}
Same file

What else settings.json configures

This page is one entry in a file that holds 2. 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. 4d ago First seen · 22 lines scan A 42bc5755d9a7

Subscribe to this mod's changes

PreToolUse is a hook published in the GitHub repository IsaiaScope/ai (2 stars, last pushed 6d 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. It is 100% identical to PreToolUse, differing in 0 lines, and is treated as a copy.