PostToolUseFailure

An automatic Bash-failure handler that runs a triage script after a Bash tool call fails. A hook is an action triggered by a particular event.

In plain words
What is it for?
It is for investigating Bash command failures in projects that use devsandbox.
Why use it?
It starts the project's failure-checking script without requiring the assistant to run it manually after every failed Bash command.

Hook for Claude Code

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/zekker6/devsandbox/post-tool-use-failure
Clone the repo
git clone --depth 1 https://github.com/zekker6/devsandbox

Made for: Claude Code.

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 58% 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 yesterday.

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

58% 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.

.claude-plugin/devsandbox-triage/hooks/hooks.json · 14 lines

What it actually says

{
  "PostToolUseFailure": [
    {
      "matcher": "Bash",
      "hooks": [
        {
          "type": "command",
          "command": "bash \"${CLAUDE_PLUGIN_ROOT}/scripts/triage.sh\"",
          "timeout": 10
        }
      ]
    }
  ]
}
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. yesterday First seen · 14 lines scan A 5a77b3977300

Subscribe to this mod's changes

PostToolUseFailure is a hook published in the GitHub repository zekker6/devsandbox (10 stars, last pushed 2d 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. It is 58% identical to SessionStart, differing in 9 lines, and is treated as a copy.