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/cwinvestments/memstack/pre-compactgit clone --depth 1 https://github.com/cwinvestments/memstackGrade A, and why
PreCompact 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 2d 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
48% identical to SessionStart — 8 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
{
"PreCompact": [
{
"hooks": [
{
"type": "command",
"command": "bash ${CLAUDE_PROJECT_DIR}/.claude/hooks/pre-compact.sh",
"timeout": 15000
}
]
}
]
}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.
- 2d ago First seen · 13 lines scan A 618946815cfd
PreCompact is a hook published in the GitHub repository cwinvestments/memstack (417 stars, last pushed 5d 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 48% identical to SessionStart, differing in 8 lines, and is treated as a copy.
Other hooks, from other repositories
PostToolUse
Runs after a tool call finishes, executing wmux-bridge.mjs via node. From openwong2kim/wmux.
PreToolUse
Runs before the agent uses a tool for Bash, Write, Edit, Bash, Task, Task and Agent tool calls, executing run-py.sh and context-warning.sh via bash (4 commands). From primeline-ai/evolving-lite.
PreCompact
Runs before the context is compacted, running an inline shell check. From zalom/plastic.
PreToolUse
Runs before the agent uses a tool for Write, Edit, Bash, Agent, Task, SendMessage and TaskStop tool calls, running bash (3 commands). From modu-ai/moai-adk.
PostToolUse
Runs after a tool call finishes, running memorix hook. From AVIDS2/memorix.
BeforeTool
Runs on the BeforeTool event for write_file, replace, run_shell_command and shell tool calls, executing before-tool.js via node. From richardcb/oh-my-gemini.