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/reidemeister94/development-skills/session-startgit clone --depth 1 https://github.com/reidemeister94/development-skillsWrote 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/reidemeister94/development-skills/session-start)<a href="https://agentmods.dev/hooks/reidemeister94/development-skills/session-start"><img src="https://agentmods.dev/badge/hooks/reidemeister94/development-skills/session-start.svg" alt="Measured on agentmods" height="20"></a>Grade A, and why
SessionStart 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
72% identical to SessionStart — 5 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
{
"SessionStart": [
{
"matcher": "startup|clear|compact",
"hooks": [
{
"type": "command",
"command": "\"${CLAUDE_PLUGIN_ROOT:-${PLUGIN_ROOT}}/hooks/session-start\"",
"timeout": 5
}
]
}
]
}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.
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 · 14 lines scan A 6aea4058907e
SessionStart is a hook published in the GitHub repository reidemeister94/development-skills (11 stars, last pushed 1mo 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 72% identical to SessionStart, differing in 5 lines, and is treated as a copy.
Other hooks, from other repositories
SessionStart
Runs when a session starts on clear, compact, startup and resume, executing session-start.sh. From LerianStudio/ring.
PreToolUse
Runs before the agent uses a tool for Bash, Write, Edit and MultiEdit tool calls, executing run-hook.cmd (5 commands). From greglas75/zuvo.
UserPromptSubmit
Runs when you submit a prompt, before the agent sees it, executing drop.py via python3. From bcanfield/agentic-tech-debt.
StopFailure
Runs on the StopFailure event for rate_limit, server_error and unknown tool calls, executing run-hook.cmd. From greglas75/zuvo.
SessionEnd
Runs when a session ends, executing session_end.py via python3. From avansaber/tailtest.
PostToolUse
Runs after a tool call finishes for Edit, Write and MultiEdit tool calls, executing post_tool_use.py via python3. From avansaber/tailtest.