PreToolUse

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

A pre-tool hook that runs checks before an agent reads or changes files and before other listed actions.

In plain words
What is it for?
Use it to run slope-guard checks during repository exploration and editing.
Why use it?
It can warn about known hazards, work outside the stated task, stale workflows, or the need to inspect the codebase index.

Hook for Claude Code

One of 5 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/srbryers/slope/pre-tool-use
Clone the repo
git clone --depth 1 https://github.com/srbryers/slope

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/srbryers/slope/pre-tool-use.svg)](https://agentmods.dev/hooks/srbryers/slope/pre-tool-use)
Your own site
<a href="https://agentmods.dev/hooks/srbryers/slope/pre-tool-use"><img src="https://agentmods.dev/badge/hooks/srbryers/slope/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 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 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.

.claude/settings.json · 124 lines

How it starts

The opening of the file, as written. The whole thing — 124 lines — stays where its author put it; the contents beside it link to each section on GitHub.

{
  "PreToolUse": [
    {
      "hooks": [
        {
          "type": "command",
          "command": "\"$CLAUDE_PROJECT_DIR\"/.claude/hooks/slope-guard.sh explore",
          "timeout": 10,
          "statusMessage": "SLOPE: Suggest checking codebase index before deep exploration"
        }
      ],
      "matcher": "Read|Glob|Grep|Edit|Write"
    },
    {
      "hooks": [
        {
          "type": "command",
          "command": "\"$CLAUDE_PROJECT_DIR\"/.claude/hooks/slope-guard.sh hazard",
          "timeout": 10,
          "statusMessage": "SLOPE: Warn about known issues in file areas being edited"
        },
        {
          "type": "command",
          "command": "\"$CLAUDE_PROJECT_DIR\"/.claude/hooks/slope-guard.sh scope-drift",
          "timeout": 10,
          "statusMessage": "SLOPE: Warn when editing files outside claimed ticket scope"
        },
        {
          "type": "command",
          "command": "\"$CLAUDE_PROJECT_DIR\"/.claude/hooks/slope-guard.sh stale-flows",
          "timeout": 10,
          "statusMessage": "SLOPE: Warn when editing files belonging to a stale flow definition"
        },
        {
          "type": "command",
          "command": "\"$CLAUDE_PROJECT_DIR\"/.claude/hooks/slope-guard.sh claim-required",
          "timeout": 10,
          "statusMessage": "SLOPE: Warn when editing code without an active sprint claim"
        }
      ],
      "matcher": "Edit|Write"
    },
    {
      "hooks": [
        {
          "type": "command",
          "command": "\"$CLAUDE_PROJECT_DIR\"/.claude/hooks/slope-guard.sh subagent-gate",
          "timeout": 10,
          "statusMessage": "SLOPE: Enforce model selection on Explore/Plan subagents"
        }
      ],
      "matcher": "Agent"
    },
    {
      "hooks": [
        {
          "type": "command",
          "command": "\"$CLAUDE_PROJECT_DIR\"/.claude/hooks/slope-guard.sh workflow-gate",
          "timeout": 10,
          "statusMessage": "SLOPE: Block ExitPlanMode until review 

Read the full file on GitHub · 124 lines

Same file

What else settings.json configures

This page is one entry in a file that holds 5. 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 · 124 lines scan A 60409faad9db

Subscribe to this mod's changes

PreToolUse is a hook published in the GitHub repository srbryers/slope (6 stars, last pushed 4d 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.