PostToolUse

PostToolUse is a hook for Claude Code from danielrosehill/Claude-Rudder. Its token cost is not measured, scanned A, original, MIT.

An automatic action that runs after a file-writing or file-editing tool finishes.

In plain words
What is it for?
Use it to watch Write and Edit operations and display a reminder when files such as CONTEXT.md, CLAUDE.md, or context-data files are modified.
Why use it?
It reminds the agent to keep human project context and the agent briefing synchronized when either context file changes.

Hook for Claude Code

Written for Claude Code: PostToolUse hook event. Also seen: mentions CLAUDE.md.

Part of the claude-rudder plugin — 25 skills, 12 commands, 2 hooks shipped together

One of 2 entries in hooks.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/danielrosehill/claude-rudder/post-tool-use
Clone the repo
git clone --depth 1 https://github.com/danielrosehill/Claude-Rudder

Made for: Claude Code.

Or install claude-rudder, the plugin that ships this one along with the rest of its 25 skills, 12 commands, 2 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 PostToolUse

README.md
[![agentmods](https://agentmods.dev/badge/hooks/danielrosehill/claude-rudder/post-tool-use.svg)](https://agentmods.dev/hooks/danielrosehill/claude-rudder/post-tool-use)
Your own site
<a href="https://agentmods.dev/hooks/danielrosehill/claude-rudder/post-tool-use"><img src="https://agentmods.dev/badge/hooks/danielrosehill/claude-rudder/post-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

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 6d 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 · 13 lines

What it actually says

{
  "PostToolUse": [
    {
      "matcher": "Write|Edit",
      "hooks": [
        {
          "type": "command",
          "command": "python3 -c \"import json,sys\nd=json.load(sys.stdin)\nfp=d.get('tool_input',{}).get('file_path','')\nif any(p in fp for p in ('CONTEXT.md','context.md','CLAUDE.md','context-data/')):\n    print('Context file modified. Remember to keep CONTEXT.md (human context) and CLAUDE.md (agent briefing) synchronized. Use /context-to-claude or /claude-to-context if needed.')\n\" 2>/dev/null || true"
        }
      ]
    }
  ]
}
Same file

What else hooks.json configures

This page is one entry in a file that holds 2. 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. 6d ago First seen · 13 lines scan A 3534a684ce54

Subscribe to this mod's changes

PostToolUse is a hook published in the GitHub repository danielrosehill/Claude-Rudder (2 stars, last pushed 1mo 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.