What happens when two devices edit the same files offline?

What you just used

This was the real filesystem, not a demonstration of one

The page loaded the NexusFS core compiled to WebAssembly — the same Rust code the command-line tool runs on a real machine. Only the storage differs: a real node writes to disk, this page keeps everything in memory. Nothing was sent anywhere; both devices lived in this tab.

The one thing this page simplifies is the network. Syncing here is a button that hands one device's records to the other in-process. Real nodes do the same thing over QUIC — sending operations first, then requesting only the content those operations turned out to need, checking every signature and every chunk hash before accepting anything.

A real node also decides how much to pull. On a low battery, a hot machine, a metered connection, or a nearly full disk, it takes the operations and defers the content — so it still knows the file exists and where it lives. When someone actually opens the file, it fetches exactly the bytes that read needs rather than waiting for the next unconstrained pass. That is the same split you saw here between the tree and the file contents.

And a real node can encrypt what it stores. Each file gets its own key, sealed to each device you have enrolled — so a replica can hold every byte of a file, verify it, replicate it onward, and still not be able to read it. Nothing on this page is encrypted, because there is only one device here and nobody to keep it from.