Files reach the books through the server: uploads by hash and size, then filed; exports (the CPA package, the 1099 worksheet, W-9s) handed over as downloads from the server, never read off disk by the agent. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01T3gXMVt7XJPi6ens1or9Dj