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/xiaoyangy/novel-studio/session-startgit clone --depth 1 https://github.com/Xiaoyangy/novel-studioWrote 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/xiaoyangy/novel-studio/session-start)<a href="https://agentmods.dev/hooks/xiaoyangy/novel-studio/session-start"><img src="https://agentmods.dev/badge/hooks/xiaoyangy/novel-studio/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.
Copies of this mod
3 near-identical copies found in the catalogue:
- PreCompact — 92% identical, 10 lines differ
- Stop — 84% identical, 10 lines differ
- PreToolUse — 81% identical, 22 lines differ
What it actually says
{
"SessionStart": [
{
"matcher": "startup|resume|clear|compact",
"hooks": [
{
"type": "command",
"command": "FOUND=; for PYBIN in python3 python py; do \"$PYBIN\" -c \"\" >/dev/null 2>&1 && { FOUND=1; break; }; done; [ -n \"$FOUND\" ] || exit 0; PROJECT_ROOT=\"${CODEX_PROJECT_DIR:-${CLAUDE_PROJECT_DIR:-}}\"; if [ -z \"$PROJECT_ROOT\" ] || [ ! -f \"$PROJECT_ROOT/.codex/hooks/story_codex_hook.py\" ]; then SEARCH_DIR=\"$PWD\"; while [ \"$SEARCH_DIR\" != \"/\" ] && [ ! -f \"$SEARCH_DIR/.codex/hooks/story_codex_hook.py\" ]; do SEARCH_DIR=\"$(dirname \"$SEARCH_DIR\")\"; done; PROJECT_ROOT=\"$SEARCH_DIR\"; fi; case \"$PROJECT_ROOT\" in \"\"|/) exit 0;; esac; HOOK=\"$PROJECT_ROOT/.codex/hooks/story_codex_hook.py\"; [ -f \"$HOOK\" ] || exit 0; CODEX_PROJECT_DIR=\"$PROJECT_ROOT\" \"$PYBIN\" \"$HOOK\" session-start",
"timeout": 10,
"statusMessage": "Loading story context",
"commandWindows": "if exist \".codex\\hooks\\story_codex_hook.py\" python \".codex\\hooks\\story_codex_hook.py\" session-start"
}
]
}
]
}What else hooks.json configures
This page is one entry in a file that holds 5. 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 · 16 lines scan A ceb434c2fe5f
SessionStart is a hook published in the GitHub repository Xiaoyangy/novel-studio (98 stars, last pushed 1mo ago), licensed Apache-2.0. 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. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other hooks, from other repositories
Stop
Runs when the agent finishes a response, executing dag-tripwire.py and ledger-tripwire.py via python3 (2 commands). From Buckeyes22/subagent-model-routing.
PreCompact
Runs before the context is compacted, running swarm claude pre-compact. From joelhooks/swarm-tools.
SessionStart
Runs when a session starts on startup, resume, clear, compact, startup and resume, executing run_in_plugin_root_with_user_path.sh with --no-project, --reap and --quiet (3 commands). From sdewell/code-quorum.
Stop
Runs when the agent finishes a response, executing hato.ts via bun with --claude-pid. From severzemlya/hato.
PostToolUse
Runs after a tool call finishes for Write and Edit tool calls, executing format_and_lint.sh. From supabase/supabase.
SessionStart
Runs when a session starts, executing on-start.js via node. From google-gemini/gemini-cli.