hook-failure-audit

hook-failure-audit is a skill for Claude Code, Codex from hoangsonww/Claude-Code-Agent-Monitor. It costs 73 tokens per session (767 once invoked), scanned A, original, MIT.

A monitoring audit that checks whether coding-agent hooks are delivering their events correctly. Hooks are automated callbacks; the audit looks for missing tool completions, session endings, and recently ingested events.

In plain words
What is it for?
Use it to check tool-event balance, missing session or subagent endings, and stale event ingestion.
Why use it?
It helps distinguish missing monitoring data from an actual coding-agent error.

Skill for Claude CodeCodex

Written for Claude Code and Codex: $ARGUMENTS substitution, but also agents/openai.yaml present. Also seen: mentions subagents.

Part of the ccam-quality plugin — 5 skills, 3 commands, 1 agent shipped together

Good fit Use it to check tool-event balance, missing session or subagent endings, and stale event ingestion.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/hoangsonww/claude-code-agent-monitor/hook-failure-audit
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.

Any agent
npx skills add hoangsonww/Claude-Code-Agent-Monitor --skill hook-failure-audit
Clone the repo
git clone --depth 1 https://github.com/hoangsonww/Claude-Code-Agent-Monitor

Made for: Claude Code, Codex.

Or install ccam-quality, the plugin that ships this one along with the rest of its 5 skills, 3 commands, 1 agent.

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 hook-failure-audit

README.md
[![agentmods](https://agentmods.dev/badge/skills/hoangsonww/claude-code-agent-monitor/hook-failure-audit/github.svg)](https://agentmods.dev/skills/hoangsonww/claude-code-agent-monitor/hook-failure-audit)
Your own site
<a href="https://agentmods.dev/skills/hoangsonww/claude-code-agent-monitor/hook-failure-audit"><img src="https://agentmods.dev/badge/skills/hoangsonww/claude-code-agent-monitor/hook-failure-audit/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for hook-failure-audit

Your own site · 80×15
<a href="https://agentmods.dev/skills/hoangsonww/claude-code-agent-monitor/hook-failure-audit"><img src="https://agentmods.dev/badge/skills/hoangsonww/claude-code-agent-monitor/hook-failure-audit.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 73 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 767 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00073 $0.00767
Opus 5 $0.00036 $0.00383
Sonnet 5 $0.00015 $0.00153
Haiku 4.5 $0.00007 $0.00077

Measured 9d ago against content hash 02967e1035f4, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

hook-failure-audit scanned grade A with 1 finding 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 9d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

- Read-only: only report what the API returns. If `curl` cannot reach `http://localhost:4820`, tell the user to start the dashboard with `npm start` from the repo root.
plugins/ccam-quality/skills/hook-failure-audit/SKILL.md · 56 lines

How it starts

The opening of the file, as written. The whole thing — 56 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Hook Failure Audit

Assess whether the hook pipeline is delivering events reliably, using the event counts and stream the dashboard already has. This is about delivery health (missing/dropped events), not about why a model errored.

Input

The user provides: $ARGUMENTS

This may be:

  • empty or "all" — run every check (default)
  • "balance" — PreToolUse/PostToolUse balance only
  • "terminators" — missing Stop/SubagentStop only
  • "freshness" — stale-ingestion check only

Data Sources

Endpoint Returns
GET /api/analytics event_types (counts per type: PreToolUse, PostToolUse, Stop, SubagentStop, SessionStart, SessionEnd), daily_events (365d), total_subagents, sessions_by_status — fleet-wide delivery balance
GET /api/stats total_sessions, total_agents, total_events, events_today — expected terminator counts and recency
GET /api/events?session_id=X Per-session stream — confirm which sessions are missing a PostToolUse, Stop, or SubagentStop

Report Sections

1. PreToolUse / PostToolUse Balance

From GET /api/analytics event_types: gap = PreToolUse − PostToolUse. A positive gap means tools whose completion hook never arrived. Report the gap as a count and as a percentage of PreToolUse. A healthy pipeline keeps this near 0%.

2. Missing Terminators

Compare Stop count against completed sessions (sessions_by_status) and SubagentStop against total_subagents/total_agents (from /api/stats). A shortfall means sessions or subagents that ran but never emitted a closing hook — likely dropped delivery or a crashed handler. Report expected vs observed for each.

3. Stale Ingestion

Check events_today from /api/stats and the tail of daily_events from analytics. If recent days are empty while sessions exist, ingestion has stalled. Report the most recent day with events and how long ago that was.

4. Localize

For the sessions with the largest gaps or missing terminators, pull GET /api/events?session_id=X and confirm which specific hook types are absent. List the offending session IDs.

Read the full file on GitHub · 56 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 9d ago First seen · 56 lines · 73 tokens per session scan A 02967e1035f4

Subscribe to this mod's changes

hook-failure-audit is a skill published in the GitHub repository hoangsonww/Claude-Code-Agent-Monitor (991 stars, last pushed 3d ago), licensed MIT. It adds 73 tokens to every session and 767 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.