PreToolUse

A group of checks that run before the agent uses Bash, Write, or Edit tools.

In plain words
What is it for?
Use it to add automatic safety and quality checks before shell commands, file edits, or commits.
Why use it?
It can catch destructive Git commands, exposed secrets, failed tests, invalid project data, and missing workflow checks before changes proceed.

Hook for Claude Code

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/t-rav/hydraflow/pre-tool-use
Clone the repo
git clone --depth 1 https://github.com/T-rav/hydraflow

Made for: Claude Code.

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 3d 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 · 103 lines

How it starts

The opening of the file, as written. The whole thing — 103 lines — stays where its author put it; the contents beside it link to each section on GitHub.

{
  "PreToolUse": [
    {
      "matcher": "Bash",
      "hooks": [
        {
          "type": "command",
          "command": "\"$CLAUDE_PROJECT_DIR\"/.claude/hooks/hf.block-destructive-git.sh",
          "timeout": 10,
          "statusMessage": "Checking for destructive git commands...",
          "_hydraflow": true
        },
        {
          "type": "command",
          "command": "\"$CLAUDE_PROJECT_DIR\"/.claude/hooks/hf.scan-secrets-before-commit.sh",
          "timeout": 30,
          "statusMessage": "Scanning for secrets in staged files...",
          "_hydraflow": true
        },
        {
          "type": "command",
          "command": "\"$CLAUDE_PROJECT_DIR\"/.claude/hooks/hf.validate-tests-before-commit.sh",
          "timeout": 120,
          "statusMessage": "Validating lint + tests before commit...",
          "_hydraflow": true
        },
        {
          "type": "command",
          "command": "\"$CLAUDE_PROJECT_DIR\"/.claude/hooks/hf.validate-functional-areas.sh",
          "timeout": 30,
          "statusMessage": "Validating functional-areas schema...",
          "_hydraflow": true
        }
      ]
    },
    {
      "matcher": "Write",
      "hooks": [
        {
          "type": "command",
          "command": "\"$CLAUDE_PROJECT_DIR\"/.claude/hooks/hf.enforce-plan-and-explore.sh",
          "timeout": 10,
          "statusMessage": "Checking for exploration and planning...",
          "_hydraflow": true
        },
        {
          "type": "command",
          "command": "\"$CLAUDE_PROJECT_DIR\"/.claude/hooks/hf.check-test-counterpart.sh",
          "timeout": 10,
          "statusMessage": "Checking for test counterpart...",
          "_hydraflow": true
        },
        {
          "type": "command",
          "command": "\"$CLAUDE_PROJECT_DIR\"/.claude/hooks/hf.enforce-migrations.sh",
          "timeout": 10,
          "statusMessage": "Checking for direct DB schema changes...",
          "_hydraflow": true
        },
        

Read the full file on GitHub · 103 lines

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. 3d ago First seen · 103 lines scan A e81425b21d5c

Subscribe to this mod's changes

PreToolUse is a hook published in the GitHub repository T-rav/hydraflow (5 stars, last pushed 3d ago), licensed Apache-2.0. 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.