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SubagentStop

SubagentStop is a hook for Claude Code from hoangsonww/Claude-Code-Agent-Monitor. Its token cost is not measured, scanned B, original, MIT.

A hook that runs a shell command when a subagent finishes its work. It sends basic information about that completed run to a local monitoring service.

In plain words
What is it for?
It helps monitor subagent activity by forwarding completion events to a local HTTP endpoint.
Why use it?
It provides an automatic record of subagent completions without requiring another manual action. The input includes the run, agent, stop reason, and time.

Hook for Claude Code

Written for Claude Code: SubagentStop hook event.

Part of the ccam-analytics plugin — 6 skills, 3 commands, 2 agents, 2 hooks shipped together

One of 2 entries in hooks.json upstream. Installing this one merges just its entry into your config; the other 1 are separate, each on its own page.

not rated 989repo +16 2d ago B scan tokens not measured original MIT

Good fit It helps monitor subagent activity by forwarding completion events to a local HTTP endpoint.

Compare 6 hooks from other repositories ↓
Install with agentmods
npx agentmods add hooks/hoangsonww/claude-code-agent-monitor/subagent-stop
View source ↗ hoangsonww/Claude-Code-Agent-Monitor hoangsonww.github.io
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.

Clone the repo
git clone --depth 1 https://github.com/hoangsonww/Claude-Code-Agent-Monitor

Made for: Claude Code.

Or install ccam-analytics, the plugin that ships this one along with the rest of its 6 skills, 3 commands, 2 agents, 2 hooks.

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 SubagentStop

README.md
[![agentmods](https://agentmods.dev/badge/hooks/hoangsonww/claude-code-agent-monitor/subagent-stop/github.svg)](https://agentmods.dev/hooks/hoangsonww/claude-code-agent-monitor/subagent-stop)
Your own site
<a href="https://agentmods.dev/hooks/hoangsonww/claude-code-agent-monitor/subagent-stop"><img src="https://agentmods.dev/badge/hooks/hoangsonww/claude-code-agent-monitor/subagent-stop/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 SubagentStop

Your own site · 80×15
<a href="https://agentmods.dev/hooks/hoangsonww/claude-code-agent-monitor/subagent-stop"><img src="https://agentmods.dev/badge/hooks/hoangsonww/claude-code-agent-monitor/subagent-stop.svg" alt="Reviewed on agentmods" width="80" 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 B 2 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Security

Grade B, and why

SubagentStop scanned grade B with 2 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 11d 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.

Sends data to an external URLmediumData exfiltration

A POST to an outside endpoint may be telemetry or may be exfiltration; either way the mod talks to somewhere, and you should know where.

"command": "jq -r '{session_id: .session_id, agent_id: .agent_id, stop_reason: .stop_reason, timestamp: now | todate}' | curl -s -X POST http://localhost:4820/api/hooks/event -H 'Content-Type: application/json' -d @- > /

Makes network callslowCapability

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

"command": "jq -r '{session_id: .session_id, agent_id: .agent_id, stop_reason: .stop_reason, timestamp: now | todate}' | curl -s -X POST http://localhost:4820/api/hooks/event -H 'Content-Type: application/json' -d @- > /
plugins/ccam-analytics/hooks/hooks.json · 13 lines

What it actually says

{
  "SubagentStop": [
    {
      "matcher": "",
      "hooks": [
        {
          "type": "command",
          "command": "jq -r '{session_id: .session_id, agent_id: .agent_id, stop_reason: .stop_reason, timestamp: now | todate}' | curl -s -X POST http://localhost:4820/api/hooks/event -H 'Content-Type: application/json' -d @- > /dev/null 2>&1 || true"
        }
      ]
    }
  ]
}
Same file

What else hooks.json configures

This page is one entry in a file that holds 2. Installing the file brings all of them; each is measured and scanned on its own page.

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. 11d ago First seen · 13 lines scan B 127ba44026a8

Subscribe to this mod's changes

SubagentStop is a hook published in the GitHub repository hoangsonww/Claude-Code-Agent-Monitor (989 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 B with 2 findings (sends data to an external url, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Claude Codeclaude-agentsclaude-skillsexpressexpressjsnode
Related

Other hooks, from other repositories

SubagentStop

Runs when a subagent finishes, executing bin.mjs via bun. From fusengine/agents.

fusengine/agents · not measured

PostToolUse

Runs after a tool call finishes for TaskCreate, TaskUpdate, Write and Edit tool calls, executing bin.mjs via bun. From fusengine/agents.

fusengine/agents · not measured

PreToolUse

Runs before the agent uses a tool for Task tool calls, executing bin.mjs via bun. From fusengine/agents.

fusengine/agents · not measured

SessionEnd

Runs when a session ends, executing bin.mjs via bun. From fusengine/agents.

fusengine/agents · not measured

PostToolUse

Runs after a tool call finishes for Write and Edit tool calls, executing format_and_lint.sh. From supabase/supabase.

supabase/supabase · not measured

SessionStart

Runs when a session starts on startup, executing install_pkgs.sh. From supabase/supabase.

supabase/supabase · not measured