Conflicts

A conflict happens when both sides of a file changed to different content since the last sync. The engine’s rule is simple: never lose an edit. Instead of picking a winner, it keeps both versions and asks you to choose.

(If both sides changed to the same content, there’s no conflict — the engine just links them with no sidecar.)

The .proton-cloud sidecar

When it detects a conflict, the daemon keeps your local file as-is and downloads the remote version alongside it, into a sidecar path using the .proton-cloud naming convention:

notes.txt   →   notes.proton-cloud.txt
archive     →   archive.proton-cloud

The sidecar (the remote version) sits next to your original (the local version). Conflict sidecars are ignored by local scans, so they don’t create new sync records or get re-uploaded, and the conflicting path is left untouched on both sides until you resolve it — so no edit is lost in the meantime.

Resolving from the CLI / filesystem

Conflict resolution is just file operations on the sidecar — there’s no special command:

• Keep your local version: delete the .proton-cloud sidecar. Removing it marks your original as modified, and the next reconcile uploads your local version over the remote.
• Adopt the remote version: replace your local file with the sidecar’s contents (e.g. move the sidecar over the original), then delete any leftover sidecar. The daemon treats the updated file as your new local version and syncs it.

Resolving in the desktop app

The app’s Conflicts screen makes this visual and safe. It shows a rail of conflicted files and a side-by-side compare — your version (local) on one side, Proton’s version (the sidecar) on the other, with a line-level diff for text files and size/timestamp metadata for binary or large files (it never fabricates a preview).

You pick one of four choices per file. Everything is staged — nothing is written to disk until you press Apply:

Choice	What it does on disk
Keep mine	Delete the sidecar; your local file uploads next pass.
Use Proton’s	Replace your file with Proton’s copy (move the sidecar over the original).
Keep both	Rename your file to name.local.ext and keep Proton’s copy too.
Decide later	Nothing is written; the file stays outstanding.

Choosing auto-advances to the next unresolved file, and the footer counts how many file operations are staged. Applying runs them and re-scans. The outstanding-conflict count is computed once and shown consistently everywhere it appears — the sidebar badge, the tab header, the Overview “needs you” card, the stat tile, and the activity ledger.

See Screens for the rest of the app.

Type conflicts

A related case is a type conflict: a path is a file on one side and a directory on the other. The engine can’t merge those, so it reports a type_conflict action. Most type conflicts are left untouched on both sides for you to sort out manually; the one exception is a local directory clashing with a same-named remote file, where the engine preserves the remote file’s content into a .proton-cloud sidecar rather than discarding it.