cc-compact

Two Claude Code CLI hooks that preserve task state, in-progress todos, and user preferences across auto-compaction, without bloating the context window.

How it works

• PreCompact runs when the CLI is about to auto-compact. It reads the session transcript, extracts the last user message + in-flight turns + the latest TodoWrite snapshot, and writes a Markdown memory file to <project>/.claude/compact-memory/<session_id>.md.
• UserPromptSubmit runs on every user prompt after the first compaction. It injects a short pointer telling the agent the memory file is available and may be read on demand.
• Preferences are agent-authored — the hook preserves a ## Preferences section on every run, but does not populate it automatically. Append with the Edit tool when the user states a lasting preference.

Install

From PyPI:

pip install cc-compact
cd /path/to/your/project
cc-compact install

The installer automatically creates or updates .claude/settings.json with the required hook entries, preserving any existing configuration. To skip this and manage settings.json manually, pass --no-settings.

Upgrading

cc-compact install creates symbolic links into the installed package by default. After upgrading the package, your hooks in every project are automatically up-to-date — no need to re-run install per project:

pipx upgrade cc-compact   # or: pip install -U cc-compact

If you prefer to copy files (e.g., for portability across machines without the package installed), use --copy:

cc-compact install --copy   # needs --force to redeploy after upgrades

Windows falls back to --copy automatically (symlinks require admin rights).

Manual (without pip)

If you prefer not to pip install, copy cc_compact/ into your project's .claude/hooks/ directly. The deployed layout is:

<project>/.claude/hooks/
├── pre_compact.py
├── user_prompt.py
└── lib/
    ├── core.py
    ├── hook_runner.py
    ├── memory.py
    └── transcript.py

Verify

Run the manual trace script:

python3 tests/trace_run.py tests/fixtures/transcript_with_todos.jsonl

Run tests

pip install -e ".[dev]"
pytest --cov=cc_compact

Debug

Every hook run appends to <project>/.claude/compact-memory/<session_id>.trace.jsonl. tail -f this file to watch the hooks work in real time.