claude-hook-builder

claude-hook-builder is a skill for Claude Code from skills-lock/skil-lock. It costs 19 tokens per session (176 once invoked), scanned A, original, Apache-2.0.

A read-only helper that examines a repository's Claude Code settings and skills, then prints a suggested hook configuration. Hooks are automated checks that run before or after tools are used.

In plain words
What is it for?
Use it to inspect existing hooks, find skills that may need tool-use controls, and generate a PreToolUse or PostToolUse block for manual pasting.
Why use it?
It saves time when setting up checks while leaving the final configuration under your review.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: reads .claude/ paths; mentions Claude Code.

Good fit Use it to inspect existing hooks, find skills that may need tool-use controls, and generate a PreToolUse or PostToolUse block for manual pasting.

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Install with agentmods
npx agentmods add skills/skills-lock/skil-lock/claude-hook-builder
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.

Any agent
npx skills add skills-lock/skil-lock --skill claude-hook-builder
Clone the repo
git clone --depth 1 https://github.com/skills-lock/skil-lock

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 claude-hook-builder

README.md
[![agentmods](https://agentmods.dev/badge/skills/skills-lock/skil-lock/claude-hook-builder/github.svg)](https://agentmods.dev/skills/skills-lock/skil-lock/claude-hook-builder)
Your own site
<a href="https://agentmods.dev/skills/skills-lock/skil-lock/claude-hook-builder"><img src="https://agentmods.dev/badge/skills/skills-lock/skil-lock/claude-hook-builder/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 claude-hook-builder

Your own site · 80×15
<a href="https://agentmods.dev/skills/skills-lock/skil-lock/claude-hook-builder"><img src="https://agentmods.dev/badge/skills/skills-lock/skil-lock/claude-hook-builder.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 19 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 176 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00019 $0.00176
Opus 5 $0.00010 $0.00088
Sonnet 5 $0.00004 $0.00035
Haiku 4.5 $0.00002 $0.00018

Measured 9d ago against content hash 4ba62f644d66, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

claude-hook-builder 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 9d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

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.

examples/drift-demo/baseline/.claude/skills/claude-hook-builder/SKILL.md · 26 lines

What it actually says

Claude hook builder

Inspects your repo's existing Claude Code configuration and prints a suggested hook block you can paste into .claude/settings.json yourself. Read-only: it never writes the file for you.

Usage

Point it at a repo and it reads the current config and skill inventory:

  • reads .claude/settings.json to see which hooks already exist
  • greps .claude/skills/**/SKILL.md for tool grants worth gating

It prints the suggested PreToolUse / PostToolUse block to stdout. You review and paste it in by hand.

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. 9d ago First seen · 26 lines · 19 tokens per session scan A 4ba62f644d66

Subscribe to this mod's changes

claude-hook-builder is a skill published in the GitHub repository skills-lock/skil-lock (3 stars, last pushed 8d ago), licensed Apache-2.0. It adds 19 tokens to every session and 176 once invoked, about $0.0001 per session on Opus 5. 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.