PostToolUse

PostToolUse is a hook for Claude Code from bitwize-music-studio/claude-ai-music-skills. Its token cost is not measured, scanned A, original, CC0-1.0.

An automatic check that runs after the coding agent writes or edits a file. It runs two Python scripts to validate a track and check that versions match.

In plain words
What is it for?
It is for projects that use the referenced music plugin and want validation after file edits.
Why use it?
It catches track and version problems immediately after changes, so they are less likely to go unnoticed.

Hook for Claude Code

Written for Claude Code: ${CLAUDE_PLUGIN_ROOT} variable.

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 bitwize-music plugin — 52 skills, 1 hook, 1 MCP server shipped together

Good fit It is for projects that use the referenced music plugin and want validation after file edits.

Compare 6 hooks from other repositories ↓
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 bitwize-music-studio/claude-ai-music-skills
Claude Code
/plugin install bitwize-music

Made for: Claude Code.

Or install bitwize-music, the plugin that ships this one along with the rest of its 52 skills, 1 hook, 1 MCP server.

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 PostToolUse

README.md
[![agentmods](https://agentmods.dev/badge/hooks/bitwize-music-studio/claude-ai-music-skills/post-tool-use/github.svg)](https://agentmods.dev/hooks/bitwize-music-studio/claude-ai-music-skills/post-tool-use)
Your own site
<a href="https://agentmods.dev/hooks/bitwize-music-studio/claude-ai-music-skills/post-tool-use"><img src="https://agentmods.dev/badge/hooks/bitwize-music-studio/claude-ai-music-skills/post-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 PostToolUse

Your own site · 80×15
<a href="https://agentmods.dev/hooks/bitwize-music-studio/claude-ai-music-skills/post-tool-use"><img src="https://agentmods.dev/badge/hooks/bitwize-music-studio/claude-ai-music-skills/post-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 original No closer match found in the catalogue.
Security

Grade A, and why

PostToolUse 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 12d 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.

hooks/hooks.json · 19 lines

What it actually says

{
  "PostToolUse": [
    {
      "matcher": "Write|Edit",
      "hooks": [
        {
          "type": "command",
          "command": "python3 ${CLAUDE_PLUGIN_ROOT}/hooks/validate_track.py",
          "timeout": 5
        },
        {
          "type": "command",
          "command": "python3 ${CLAUDE_PLUGIN_ROOT}/hooks/check_version_sync.py",
          "timeout": 5
        }
      ]
    }
  ]
}
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. 12d ago First seen · 19 lines scan A 81c1be2c7713

Subscribe to this mod's changes

PostToolUse is a hook published in the GitHub repository bitwize-music-studio/claude-ai-music-skills (483 stars, last pushed yesterday), licensed CC0-1.0. 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 2026-08-30.