The system daemon runs as its own user behind ProtectHome, so it can neither read a file a desktop app wrote for Add nor write one back for Materialize - redoal on the system varde failed every get with EACCES. Put imports base64 bytes carried in the request and Read returns a raw blob's bytes in the reply, both up to MAX_INLINE_BYTES (16 MiB). Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>