Small files ride inside the change; large files are encrypted trees that go straight to storage, and the node signs a receipt that syncs as the one readable field. Name, type and key stay sealed.

It is the rebuilt file node and verifiable backup status.

A file is attached to an object. There are no standalone files. The attach returns before any network work.

Under four kilobytes, the bytes ride inside the change itself. Durable by construction. They never reach a file node.

Larger files are encrypted and chunked into a tree, each chunk named by its hash. Stored locally first. Backed up in the background.

In the old file node, bytes passed through the node. In the rebuilt one they go straight to storage. The node signs a receipt when the bytes are there.

The receipt is a readable field on the file's row, so it syncs. Every member sees the file flip to durable. Backup status is verifiable, not assumed.

This is the one field of yours a node can read: the root hash, the size, the receipt. The name, the type, and the key stay sealed for members.

Check yourself. How does another member learn that a file is backed up?