PreCompact

PreCompact is a hook for Claude Code from Mexregkan/claude-for-researchers. Its token cost is not measured, scanned A, original, MIT.

A pre-compaction hook that runs a shell script before the coding agent compresses its conversation context.

In plain words
What is it for?
Use it to stamp project instructions and save task-log state before context compression.
Why use it?
It helps preserve project notes and a task snapshot before earlier conversation details are condensed.

Hook for Claude Code

Written for Claude Code: PreCompact hook event. Also seen: reads .claude/ paths; mentions CLAUDE.md.

One of 3 entries in settings.json upstream. Installing this one merges just its entry into your config; the other 2 are separate, each on its own page.

Good fit Use it to stamp project instructions and save task-log state before context compression.

Compare 6 hooks from other repositories ↓
Install with agentmods
npx agentmods add hooks/mexregkan/claude-for-researchers/pre-compact
Install

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.

Clone the repo
git clone --depth 1 https://github.com/Mexregkan/claude-for-researchers

Made for: Claude Code.

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/mexregkan/claude-for-researchers/pre-compact/github.svg)](https://agentmods.dev/hooks/mexregkan/claude-for-researchers/pre-compact)
Your own site
<a href="https://agentmods.dev/hooks/mexregkan/claude-for-researchers/pre-compact"><img src="https://agentmods.dev/badge/hooks/mexregkan/claude-for-researchers/pre-compact/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for PreCompact

Your own site · 80×15
<a href="https://agentmods.dev/hooks/mexregkan/claude-for-researchers/pre-compact"><img src="https://agentmods.dev/badge/hooks/mexregkan/claude-for-researchers/pre-compact.svg" alt="Reviewed on agentmods" width="80" 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. A grade says what 26 rules found in the file — not that it is safe.
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 10d 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.

starter/.claude/settings.json · 14 lines

What it actually says

{
  "PreCompact": [
    {
      "_comment": "Runs before Claude compresses the conversation context. Stamps CLAUDE.md and snapshots the task log so you never lose track of where you were.",
      "hooks": [
        {
          "type": "command",
          "command": "bash .claude/hooks/pre-compact.sh 2>/dev/null || true",
          "timeout": 10
        }
      ]
    }
  ]
}
Same file

What else settings.json configures

This page is one entry in a file that holds 3. 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. 10d ago First seen · 14 lines scan A 815036adce5e

Subscribe to this mod's changes

PreCompact is a hook published in the GitHub repository Mexregkan/claude-for-researchers (52 stars, last pushed 7d 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.