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.
npx agentmods add hooks/bar181/bar-observatory/subagent-stopgit clone --depth 1 https://github.com/bar181/bar-observatoryWrote 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.
[](https://agentmods.dev/hooks/bar181/bar-observatory/subagent-stop)<a href="https://agentmods.dev/hooks/bar181/bar-observatory/subagent-stop"><img src="https://agentmods.dev/badge/hooks/bar181/bar-observatory/subagent-stop.svg" alt="Measured on agentmods" height="20"></a>Grade A, and why
SubagentStop 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 3d 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.
This is a copy
86% identical to SessionStart — 4 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.
What it actually says
{
"SubagentStop": [
{
"matcher": "",
"hooks": [
{
"type": "command",
"command": "bar-hook SubagentStop"
}
]
}
]
}What else hooks.json configures
This page is one entry in a file that holds 21. Installing the file brings all of them; each is measured and scanned on its own page.
- Hook ConfigChange A not measured
- Hook InstructionsLoaded A not measured
- Hook Notification A not measured
- Hook PermissionDenied A not measured
- Hook PermissionRequest A not measured
- Hook PostCompact A not measured
- Hook PostToolBatch A not measured
- Hook PostToolUse A not measured
- Hook PostToolUseFailure A not measured
- Hook PreCompact A not measured
- Hook PreToolUse A not measured
- Hook SessionEnd A not measured
- Hook SessionStart A not measured
- Hook Stop A not measured
- Hook StopFailure A not measured
- Hook SubagentStart A not measured
- Hook TaskCompleted A not measured
- Hook TaskCreated A not measured
- Hook UserPromptExpansion A not measured
- Hook UserPromptSubmit A not measured
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.
- 3d ago First seen · 13 lines scan A 06b9bddb1a18
SubagentStop is a hook published in the GitHub repository bar181/bar-observatory (22 stars, last pushed 6d 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 86% identical to SessionStart, differing in 4 lines, and is treated as a copy.
Other hooks, from other repositories
PreToolUse
Runs before the agent uses a tool for Read, Grep, Bash, Bash, Skill, Task, Agent, mcp__.*, Edit, Write, MultiEdit and NotebookEdit tool calls, executing py-launch.sh via sh (6 commands). From AleksandarBisevac/claude-plugins.
PostToolUse
Runs after a tool call finishes for Edit, Write, MultiEdit, NotebookEdit and Bash tool calls, executing py-launch.sh via sh (6 commands). From AleksandarBisevac/claude-plugins.
UserPromptSubmit
Runs when you submit a prompt, before the agent sees it, executing py-launch.sh via sh. From AleksandarBisevac/claude-plugins.
Stop
Runs when the agent finishes a response, executing py-launch.sh via sh. From AleksandarBisevac/claude-plugins.
SessionStart
Runs when a session starts, executing session-start-status.sh via bash. From Enovatr-Labs/SpecRoute.
PreToolUse
Runs before the agent uses a tool for Bash tool calls, executing pre-bash-sanitize.sh via bash. From Enovatr-Labs/SpecRoute.