PostToolUseFailure

PostToolUseFailure is a hook for coding agents from RetainDB/RetainDB. Its token cost is not measured, scanned A, a copy of PostToolUseFailure, Apache-2.0.

A hook configuration that runs a JavaScript program after another tool call fails. A hook is an automatic action triggered by a particular event.

In plain words
What is it for?
Use it to trigger post-tool-failure.mjs whenever a tool call reports an error.
Why use it?
It provides a defined place to handle tool errors after they occur instead of leaving failures without follow-up processing.

Hook

Runs only inside a plugin — its command needs a path that Claude Code sets for a plugin’s own hooks and for nothing else, and the catalogue could not identify which plugin ships it.

One of 12 entries in hooks.json — they are configured in one file and arrive together.

Install

Getting it into your agent

There is no command for this one: it runs only inside a plugin, and the catalogue could not identify which plugin ships it. The source is linked below.

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 PostToolUseFailure

README.md
[![agentmods](https://agentmods.dev/badge/hooks/retaindb/retaindb/post-tool-use-failure.svg)](https://agentmods.dev/hooks/retaindb/retaindb/post-tool-use-failure)
Your own site
<a href="https://agentmods.dev/hooks/retaindb/retaindb/post-tool-use-failure"><img src="https://agentmods.dev/badge/hooks/retaindb/retaindb/post-tool-use-failure.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 100% copy Near-identical to another mod in the catalogue.
Security

Grade A, and why

PostToolUseFailure 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 4d 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

100% identical to PostToolUseFailure — 0 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.

packages/local/plugin/hooks/hooks.json · 12 lines

What it actually says

{
  "PostToolUseFailure": [
    {
      "hooks": [
        {
          "type": "command",
          "command": "node \"${CLAUDE_PLUGIN_ROOT}/scripts/post-tool-failure.mjs\""
        }
      ]
    }
  ]
}
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. 4d ago First seen · 12 lines scan A a68b8463eccf

Subscribe to this mod's changes

PostToolUseFailure is a hook published in the GitHub repository RetainDB/RetainDB (54 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 100% identical to PostToolUseFailure, differing in 0 lines, and is treated as a copy.