Use it to check for uncommitted changes immediately before context compaction and display a reminder when they exist.

It warns you that work may not be committed before session details are compacted, reducing the chance of overlooking unfinished changes.

How derjochenmeyer/claude-code-craft configures Claude Code

claude-code-craft: Hook for Claude Code

.claude/settings.json

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

A pre-compaction hook that checks whether the Git working directory has uncommitted changes before the coding session's context is shortened. Git is the version-control system commonly used to track code changes.

In plain words

What is it for?: Use it to check for uncommitted changes immediately before context compaction and display a reminder when they exist.
Why use it?: It warns you that work may not be committed before session details are compacted, reducing the chance of overlooking unfinished changes.

Written for Claude Code: PreCompact hook event.

This is derjochenmeyer/claude-code-craft's own configuration. It tells Claude Code how to work on claude-code-craft itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything claude-code-craft configures →

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.

Reuse

Borrowing it

Nothing to install: this file belongs to derjochenmeyer/claude-code-craft. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/derjochenmeyer/claude-code-craft/main/.claude/settings.json

Clone the repo

git clone --depth 1 https://github.com/derjochenmeyer/claude-code-craft

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.

README.md

[![agentmods](https://agentmods.dev/badge/hooks/derjochenmeyer/claude-code-craft/pre-compact/github.svg)](https://agentmods.dev/hooks/derjochenmeyer/claude-code-craft/pre-compact)

Your own site

<a href="https://agentmods.dev/hooks/derjochenmeyer/claude-code-craft/pre-compact"><img src="https://agentmods.dev/badge/hooks/derjochenmeyer/claude-code-craft/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.

Your own site · 80×15

<a href="https://agentmods.dev/hooks/derjochenmeyer/claude-code-craft/pre-compact"><img src="https://agentmods.dev/badge/hooks/derjochenmeyer/claude-code-craft/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 2mo 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.

.claude/settings.json · 14 lines

What it actually says

{
  "PreCompact": [
    {
      "matcher": "",
      "hooks": [
        {
          "type": "command",
          "command": "git diff --quiet HEAD 2>/dev/null && printf '{\"decision\":\"allow\"}' || printf '{\"decision\":\"allow\",\"systemMessage\":\"[craft] Uncommitted changes detected. Consider committing before compaction to preserve this session.\"}'",
          "timeout": 5
        }
      ]
    }
  ]
}

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.

2mo ago First seen · 14 lines scan A e4bb6ac11ab8

Subscribe to this mod's changes

PreCompact is a hook published in the GitHub repository derjochenmeyer/claude-code-craft (2 stars, last pushed 6mo 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.

Git and workflow

PreCompact next to 6 hooks from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
PreCompactderjochenmeyer/claude-code-craft	Hook	2	6mo ago	MIT	A	—	Claude Code
PostToolUsesupabase/supabase	Hook	115k	yesterday	Apache-2.0	A	—	Claude Code
SessionStartsupabase/supabase	Hook	115k	yesterday	Apache-2.0	A	—	Claude Code
SessionStartgoogle-gemini/gemini-cli	Hook	109k	yesterday	Apache-2.0	A	—	Claude Code
PreToolUseapache/superset	Hook	75k	yesterday	Apache-2.0	A	—	Claude Code
PreToolUseanthropics/claude-cookbooks	Hook	54k	2d ago	MIT	A	—	Claude Code
PostToolUseanthropics/claude-plugins-official	Hook	46k	yesterday	Apache-2.0	A	—	Claude Code