PreCompact

PreCompact is a hook for coding agents from Cyvid7-Darus10/claude-code-config. Its token cost is not measured, scanned A, original, MIT.

A pre-compaction hook that runs a script before an AI coding session's context is shortened.

In plain words
What is it for?
Use it to trigger the configured state-saving script whenever context compaction begins.
Why use it?
It saves session state before older conversation details are compressed, reducing the chance of losing useful context.

Hook

Runs only inside a plugin — its command needs a path that Claude Code sets for a plugin’s own hooks and for nothing else, and the catalogue could not identify which plugin ships it.

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

Install

Getting it into your agent

There is no command for this one: it runs only inside a plugin, and the catalogue could not identify which plugin ships it. The source is linked below.

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/cyvid7-darus10/claude-code-config/pre-compact.svg)](https://agentmods.dev/hooks/cyvid7-darus10/claude-code-config/pre-compact)
Your own site
<a href="https://agentmods.dev/hooks/cyvid7-darus10/claude-code-config/pre-compact"><img src="https://agentmods.dev/badge/hooks/cyvid7-darus10/claude-code-config/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 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.

hooks/hooks.json · 14 lines

What it actually says

{
  "PreCompact": [
    {
      "matcher": "*",
      "hooks": [
        {
          "type": "command",
          "command": "node \"${CLAUDE_PLUGIN_ROOT}/scripts/hooks/run-with-flags.js\" \"pre:compact\" \"scripts/hooks/pre-compact.js\" \"standard,strict\""
        }
      ],
      "description": "Save state before context compaction"
    }
  ]
}
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. 3d ago First seen · 14 lines scan A 9957fccb7a96

Subscribe to this mod's changes

PreCompact is a hook published in the GitHub repository Cyvid7-Darus10/claude-code-config (2 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. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.