agentmods.dev

PreToolUse

A check that runs before an AI coding agent uses a tool. It executes a shell command through the configured PreToolUse hook.

In plain words
What is it for?
Use it to run the configured ccmonitor check before each tool use.
Why use it?
It can inspect or control tool calls before they happen, adding a checkpoint to the agent’s actions.

Hook

2 6mo ago A scan tokens not measured copy · 91% MIT
View the source file MartinWickman/ccmonitor
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/martinwickman/ccmonitor/pre-tool-use
Clone the repo
git clone --depth 1 https://github.com/MartinWickman/ccmonitor
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 91% 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 2d 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

91% identical to SessionStart — 2 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.

plugin/hooks/hooks.json · 13 lines

What it actually says

{
  "PreToolUse": [
    {
      "matcher": "",
      "hooks": [
        {
          "type": "command",
          "command": "ccmonitor.exe hook 2>/dev/null || ccmonitor hook"
        }
      ]
    }
  ]
}
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. 2d ago First seen · 13 lines scan A 7836a201f92b

Subscribe to this mod's changes

PreToolUse is a hook published in the GitHub repository MartinWickman/ccmonitor (2 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. It is 91% identical to SessionStart, differing in 2 lines, and is treated as a copy.

claude-code-cliclaude-code-plugin
Related

Other hooks, from other repositories

PreToolUse

Runs before the agent uses a tool for Read, Edit, Write, Read, Grep, Task and Edit tool calls, executing pre-tool-use-broadcast.mjs, path-rules.mjs, tldr-read-enforcer.mjs, smart-search-router.mjs, tldr-context-inject.mjs, arch-context-inject.mjs, file-claims.mjs, edit-context-inject.mjs and signature-helper.mjs via…

parcadei/Continuous-Claude-v3 · not measured

SessionStart

Runs when a session starts on resume, compact, clear, startup and resume, executing persist-project-dir.sh, session_start.sh, session-register.mjs, hook_launcher.py, session-start-continuity.mjs and session-start-tldr-cache.mjs via bash (6 commands). From parcadei/Continuous-Claude-v3.

parcadei/Continuous-Claude-v3 · not measured

UserPromptSubmit

Runs when you submit a prompt, before the agent sees it, executing skill-activation-prompt.mjs, hook_launcher.py, memory-awareness.mjs, impact-refactor.mjs and user_prompt_submit.sh via node (5 commands). From parcadei/Continuous-Claude-v3.

parcadei/Continuous-Claude-v3 · not measured

Stop

Runs when the agent finishes a response, executing hook_launcher.py, stop_hook.sh and compiler-in-the-loop-stop.mjs via uv (3 commands). From parcadei/Continuous-Claude-v3.

parcadei/Continuous-Claude-v3 · not measured

SessionEnd

Runs when a session ends, executing session-end-cleanup.mjs, session-outcome.mjs and session_end.sh via node (3 commands). From parcadei/Continuous-Claude-v3.

parcadei/Continuous-Claude-v3 · not measured

PreCompact

Runs before the context is compacted, executing pre-compact-continuity.mjs via node. From parcadei/Continuous-Claude-v3.

parcadei/Continuous-Claude-v3 · not measured