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PreCompact

PreCompact is a hook for coding agents from sdsrss/claude-mem-lite. Its token cost is not measured, scanned A, original, MIT.

A pre-compaction hook is an automatic command that runs just before an agent's conversation context is shortened. This one launches a Node.js script with the `pre-compact` event.

In plain words
What is it for?
Use it to trigger the `hook.mjs` pre-compaction behavior through `hook-launcher.mjs`.
Why use it?
It provides a last chance to run saved preparation logic before context is compacted and some conversation detail may be removed.

Hook

Runs only inside its plugin — its command needs a path that Claude Code sets for a plugin’s own hooks and for nothing else. Install the plugin, not this.

Part of the claude-mem-lite plugin — 8 commands, 7 hooks, 1 MCP server shipped together

One of 7 entries in hooks.json — they are configured in one file and arrive together.

not rated 56 today A scan tokens not measured original MIT
View the source file sdsrss/claude-mem-lite
Install

Getting it into your agent

This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.

Claude Code
/plugin marketplace add sdsrss/claude-mem-lite
Claude Code
/plugin install claude-mem-lite

Or install claude-mem-lite, the plugin that ships this one along with the rest of its 8 commands, 7 hooks, 1 MCP server.

Wrote 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.

agentmods badge for PreCompact

README.md
[![agentmods](https://agentmods.dev/badge/hooks/sdsrss/claude-mem-lite/pre-compact.svg)](https://agentmods.dev/hooks/sdsrss/claude-mem-lite/pre-compact)
Your own site
<a href="https://agentmods.dev/hooks/sdsrss/claude-mem-lite/pre-compact"><img src="https://agentmods.dev/badge/hooks/sdsrss/claude-mem-lite/pre-compact.svg" alt="Measured on agentmods" height="20"></a>
Per session not measured What this adds to a session before it is invoked.
When invoked not measured Not applicable: nothing here is loaded into a session.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Security

Grade 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 4d 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.

hooks/hooks.json · 14 lines

What it actually says

{
  "PreCompact": [
    {
      "matcher": "*",
      "hooks": [
        {
          "type": "command",
          "command": "node \"${CLAUDE_PLUGIN_ROOT}/scripts/hook-launcher.mjs\" hook.mjs pre-compact",
          "timeout": 5
        }
      ]
    }
  ]
}
Same file

What else hooks.json configures

This page is one entry in a file that holds 7. Installing the file brings all of them; each is measured and scanned on its own page.

Changes

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.

  1. 4d ago First seen · 14 lines scan A 6d8422fc8fdf

Subscribe to this mod's changes

PreCompact is a hook published in the GitHub repository sdsrss/claude-mem-lite (56 stars, last pushed today), 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.

Memory and contextclaude-codefts5hooksmcppersistence
Related

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SubagentStop

Runs when a subagent finishes, executing tlc-cleanup.sh and continuous-execution-hook.sh via bash (2 commands). From johanolofsson72/Claude.

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SessionStart

Runs when a session starts on startup, clear and compact, executing smart-install.js and bun-wrapper.cjs via node (4 commands). From nhevers/MoltBrain.

nhevers/MoltBrain · not measured

Notification

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prime-radiant-inc/claude-plugin-cxdb-integration · not measured

PostToolUse

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