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/matt1398/claude-devtools/session-startgit clone --depth 1 https://github.com/matt1398/claude-devtoolsGrade 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 yesterday.
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.
What it actually says
{
"SessionStart": [
{
"matcher": "compact",
"hooks": [
{
"type": "command",
"command": "echo '[Post-compaction context reminder]\n- Package manager: pnpm only (not npm/yarn)\n- Path aliases: @main/*, @renderer/*, @shared/*, @preload/*\n- Electron 3-process: main/ (Node), preload/ (bridge), renderer/ (React), shared/ (cross-process)\n- isMeta: false = real user message, true = internal/system message\n- Chunk types: UserChunk, AIChunk, SystemChunk, CompactChunk\n- State: Zustand slices pattern (data, selectedId, loading, error)\n- Styling: Tailwind with CSS variables (bg-surface, text-text, border-border)\n- Naming: PascalCase services/components, camelCase utils, UPPER_SNAKE constants\n- Barrel exports: import from domain index.ts\n- New IPC: channel in preload/constants → handler in main/ipc → method in preload/index.ts\n- PostToolUse hook auto-runs eslint+prettier on edited files\n- PreToolUse hook blocks edits to pnpm-lock.yaml, .env, dist/, node_modules/'"
}
]
}
]
}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.
- yesterday First seen · 13 lines scan A f6c4e98c6d8c
SessionStart is a hook published in the GitHub repository matt1398/claude-devtools (3,885 stars, last pushed 3mo 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. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other hooks, from other repositories
PreToolUse
Runs before the agent uses a tool for Bash tool calls, executing pre-commit.sh. From PixelPaw-Labs/codex-trace.
UserPromptSubmit
Runs when you submit a prompt, before the agent sees it, executing pipeline-prompt.sh. From Pierry/harness-kit.
SessionStart
Runs when a session starts, executing session-lifecycle-hook.mjs via node. From LovelaceLoom/grok-plugin-cc.
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 on startup, executing install_pkgs.sh. From supabase/supabase.
SessionStart
Runs when a session starts, executing on-start.js via node. From google-gemini/gemini-cli.