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PreToolUse

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

A group of checks that runs before an agent uses Bash or Read tools.

In plain words
What is it for?
It is for enforcing safety and project-workflow checks around command execution and file reading.
Why use it?
It helps catch unsafe shell commands, banned wording, missing baseline checks, and required context before tool use.

Hook for Claude Code

Written for Claude Code: ${CLAUDE_PLUGIN_ROOT} variable. Also seen: names the NotebookEdit tool.

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 claudemd plugin — 16 commands, 1 agent, 7 hooks shipped together

One of 7 entries in hooks.json upstream. Installing this one merges just its entry into your config; the other 6 are separate, each on its own page.

not rated 3repo changed 20d ago A scan tokens not measured copy · 66% MIT

Good fit It is for enforcing safety and project-workflow checks around command execution and file reading.

Compare 6 hooks from other repositories ↓
View source ↗ sdsrss/claudemd npmjs.com
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 sdsrss/claudemd
Claude Code
/plugin install claudemd

Made for: Claude Code.

Or install claudemd, the plugin that ships this one along with the rest of its 16 commands, 1 agent, 7 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/sdsrss/claudemd/pre-tool-use/github.svg)](https://agentmods.dev/hooks/sdsrss/claudemd/pre-tool-use)
Your own site
<a href="https://agentmods.dev/hooks/sdsrss/claudemd/pre-tool-use"><img src="https://agentmods.dev/badge/hooks/sdsrss/claudemd/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/sdsrss/claudemd/pre-tool-use"><img src="https://agentmods.dev/badge/hooks/sdsrss/claudemd/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 66% 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 20d 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

66% identical to SessionStart — 49 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.

hooks/hooks.json · 54 lines

What it actually says

{
  "PreToolUse": [
    {
      "matcher": "Bash",
      "hooks": [
        {
          "type": "command",
          "command": "bash \"${CLAUDE_PLUGIN_ROOT}/hooks/pre-bash-safety-check.sh\"",
          "timeout": 3
        },
        {
          "type": "command",
          "command": "bash \"${CLAUDE_PLUGIN_ROOT}/hooks/spec-module-gate.sh\"",
          "timeout": 3
        },
        {
          "type": "command",
          "command": "bash \"${CLAUDE_PLUGIN_ROOT}/hooks/banned-vocab-check.sh\"",
          "timeout": 3
        },
        {
          "type": "command",
          "command": "bash \"${CLAUDE_PLUGIN_ROOT}/hooks/ship-baseline-check.sh\"",
          "timeout": 5
        },
        {
          "type": "command",
          "command": "bash \"${CLAUDE_PLUGIN_ROOT}/hooks/memory-read-check.sh\"",
          "timeout": 3
        }
      ]
    },
    {
      "matcher": "Read",
      "hooks": [
        {
          "type": "command",
          "command": "bash \"${CLAUDE_PLUGIN_ROOT}/hooks/session-extended-read.sh\"",
          "timeout": 3
        }
      ]
    },
    {
      "matcher": "Edit|Write|NotebookEdit|Bash",
      "hooks": [
        {
          "type": "command",
          "command": "bash \"${CLAUDE_PLUGIN_ROOT}/hooks/cross-repo-write-check.sh\"",
          "timeout": 3
        }
      ]
    }
  ]
}
Same file

What else hooks.json configures

This page is one entry in a file that holds 7. 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. 20d ago Changed · +5 lines 40068730aff9
  2. 21d ago Changed · +10 lines 62c3b614212b
  3. 1mo ago First seen · 39 lines scan A b90aaef474db

Subscribe to this mod's changes

PreToolUse is a hook published in the GitHub repository sdsrss/claudemd (3 stars, last pushed today), 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 66% identical to SessionStart, differing in 49 lines, and is treated as a copy.

Claude Codeclaude-code-plugincode-qualitycommit-linthooksnpm-cli
Related

Other hooks, from other repositories

PostToolUse

Runs after a tool call finishes for Edit and Write tool calls, running an inline shell check. From nikolaypaskov/claudeconf-plugin.

nikolaypaskov/claudeconf-plugin · not measured

SessionStart

Runs when a session starts, executing session-start.sh via bash. From prime-radiant-inc/claude-plugin-cxdb-integration.

prime-radiant-inc/claude-plugin-cxdb-integration · not measured

Notification

Runs when the agent sends a notification, executing notification.sh via bash. From prime-radiant-inc/claude-plugin-cxdb-integration.

prime-radiant-inc/claude-plugin-cxdb-integration · not measured

PreToolUse

Runs before the agent uses a tool for Bash tool calls, running an inline shell check. From apache/superset.

apache/superset · not measured

PreToolUse

Runs before the agent uses a tool, executing pre-write.sh and pre-bash.sh (2 commands). From anthropics/claude-cookbooks.

anthropics/claude-cookbooks · not measured

PostToolUse

Runs after a tool call finishes for Bash tool calls, executing hooks.sh via sh (3 commands). From anthropics/claude-plugins-official.

anthropics/claude-plugins-official · not measured