Long chats summarize themselves into project memory.
If you run several Claude Code chats about one project, each re-reads files and re-derives the same context, burning tokens. This hook counts tool calls and, past a threshold, has Claude drop a tight summary of the chat into project memory. Parallel and future chats load that instead.
One PostToolUse hook. Install it and forget it; every chat checkpoints itself.
Keyed by session, so each long chat checkpoints independently.
Captures what a future chat would re-derive: what changed, key decisions and why, open threads.
MEMORY_CHECKPOINT_EVERY sets the cadence; 250 tool calls by default.
The installer merges into settings.json without touching your existing hooks, and re-running never duplicates.
Writes into Claude Code's own auto-memory directory, derived from your project path.
git clone https://github.com/jay739/claude-memory-checkpoint
cd claude-memory-checkpoint
./install.sh