PostToolUse

A rule that runs a command after every tool call finishes. In this case, it runs a governance script from the Agentic Control Plane, a system for monitoring and controlling coding-agent actions.

In plain words
What is it for?
Use it to apply governance, auditing, or policy checks after shell commands and other tool calls.
Why use it?
It provides an automatic post-action check or record without requiring the agent to remember to run it.

Hook

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/agentic-control-plane/codex-acp-plugin/post-tool-use
Clone the repo
git clone --depth 1 https://github.com/agentic-control-plane/codex-acp-plugin
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 2d 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 · 14 lines

What it actually says

{
  "PostToolUse": [
    {
      "matcher": ".*",
      "hooks": [
        {
          "type": "command",
          "command": "ACP_HARNESS=codex ACP_CLIENT=codex-plugin node \"$CLAUDE_PLUGIN_ROOT/bin/govern.mjs\"",
          "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. 2d ago First seen · 14 lines scan A b9c77ea1c646

Subscribe to this mod's changes

PostToolUse is a hook published in the GitHub repository agentic-control-plane/codex-acp-plugin (1 stars, last pushed 18d 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.