An after-tool hook that runs a validation script whenever Claude Code uses Write or Edit.

It is for automatically checking generated or edited reports with validate-report.sh.

It catches report problems immediately after files are changed.

PostToolUse — Hook for coding agents by krokoko: An after-tool hook that runs a validation script whenever…

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 krokoko/cairn

Claude Code

/plugin install codebase-ai-readiness

Or install codebase-ai-readiness, the plugin that ships this one along with the rest of its 2 skills, 1 hook.

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.

README.md

[![agentmods](https://agentmods.dev/badge/hooks/krokoko/cairn/post-tool-use.svg)](https://agentmods.dev/hooks/krokoko/cairn/post-tool-use)

Your own site

<a href="https://agentmods.dev/hooks/krokoko/cairn/post-tool-use"><img src="https://agentmods.dev/badge/hooks/krokoko/cairn/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 59% copy Near-identical to another mod 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 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.

Origin

This is a copy

59% identical to SessionStart — 9 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

plugins/codebase-ai-readiness/hooks/hooks.json · 14 lines

What it actually says

{
  "PostToolUse": [
    {
      "matcher": "Write|Edit",
      "hooks": [
        {
          "type": "command",
          "command": "${CLAUDE_PLUGIN_ROOT}/scripts/validate-report.sh",
          "timeout": 30
        }
      ]
    }
  ]
}

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.

3d ago First seen · 14 lines scan A b94a946c1424

Subscribe to this mod's changes

PostToolUse is a hook published in the GitHub repository krokoko/cairn (13 stars, last pushed 2mo 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. It is 59% identical to SessionStart, differing in 9 lines, and is treated as a copy.

Autonomous Agents agentic-coding ai-agents ai-readiness code-verification

PostToolUse

Getting it into your agent

Wrote this? Show the measurements

Grade A, and why

Nothing flagged

This is a copy

What it actually says

What this file has done since we first saw it

Other hooks, from other repositories

SessionStart

UserPromptSubmit

PostToolUse

PostToolUseFailure

SessionEnd

PreToolUse