ContextFS gives Claude Code a second brain. Run contextfs build once and every source file gets a plain-text summary. From then on, Claude reads ~13,000 tokens instead of ~69,000 — that's 81% fewer tokens per file. When you close a session, ContextFS auto-compacts it into decisions, open questions, and next steps. Open a new session and Claude Code picks up exactly where you left off. Less context. Less tokens. Less money.