Halyard

Two-way folder sync for Proton Drive on GNOME.

This is a third-party application not officially supported by Proton. It is not affiliated with, endorsed by, or produced by Proton AG. It is built on Proton's open-source Drive SDK, but Proton provides no support for it.

Pick a local folder, pick a Drive folder, and Halyard keeps them in step in both directions. Add as many pairs as you like; folders you have not paired are never touched.

~/Documents/Work   ↔  /Work
~/Pictures/2026    ↔  /Photos/2026
~/notes            ↔  /Notes

How sync behaves

Situation	What Halyard does
Same file edited in both places	Keeps both. The remote version keeps the original name. The local version gets a name such as file (conflict 2026-07-19).ext.
File deleted on one side and unchanged on the other	Applies the deletion. The remote copy remains recoverable from Proton's Trash.
File deleted on one side and edited on the other	Keeps the edit. The file is restored or re-uploaded.
File renamed or moved	Detected as a move, so nothing is re-transferred. A renamed 4 GB file costs one API call, not 4 GB.

When the safe answer is unclear, Halyard keeps both copies.

Requirements

• GNOME on Wayland or X11, with a Secret Service provider such as gnome-keyring
• Node 22+
• Bun, which applies the required patch for @protontech/crypto
• Python 3 with PyGObject, GTK 4 and libadwaita 1

Install

git clone --recurse-submodules https://github.com/VottonDev/halyard
cd halyard
./packaging/install.sh    # fetches + builds the pinned Proton SDK, then the daemon
systemctl --user enable --now halyard-daemon.service
halyard

Sign-in happens through Proton in your browser, so Halyard never sees your password. It stores the resulting session in your keyring and encrypts its local metadata cache.

Using it

Add a pair with the + button. Choose a local folder, then select or create its Drive folder. Sync starts at once.

Closing the window does not stop syncing. Choose Quit from the app menu or run systemctl --user stop halyard-daemon to stop the service. Halyard runs entirely as your user and never needs sudo.

Conflicts appear in their own view. Both copies already exist on disk by the time you see one. Keep local restores your copy to the original name. Keep remote discards the preserved copy. Dismiss leaves both files and clears the entry.

Excluding folders

A pair can cover a broad folder while leaving parts of it alone. For example, sync ~/Documents but not the GitHub checkout inside it. Patterns are gitignore-style and relative to the pair root:

Pattern	Matches
GitHub	a folder named GitHub at any depth, and everything under it
/GitHub	only at the top level of the pair
Archive/old	an anchored path (any interior slash anchors)
*.iso	a glob within one path segment
**/cache	an explicit any-depth match

Excluding a path never deletes it. Existing content stays in place locally and on Drive but is no longer tracked. Removing an exclusion later merges both sides again. Negation patterns such as !pattern are not supported.

node_modules is not excluded by default. A single JavaScript project can hold hundreds of megabytes across tens of thousands of reinstallable files, so exclude it explicitly if you sync code.

What is not synced

Halyard skips .git, .DS_Store, lost+found, common temporary files, its own partial downloads, and symlinks. Everything else syncs, including dotfiles. Use git rather than Halyard to sync repositories.

Development

git submodule update --init
./scripts/build-proton-sdk.sh
cd daemon
bun install
bun run test
node scripts/build.mjs
./node_modules/.bin/tsc --noEmit

The daemon runs from dist/, so rebuild it after changing daemon/src/. For UI work, run the mock daemon and app together:

cd ui
./run-dev.sh

Do not run daemon/scripts/live-test*.mjs without checking first. Those scripts write to the connected Proton Drive account.

Troubleshooting

Run the doctor first. It checks local dependencies without touching account data.

cd daemon && bun run doctor

Then check the service log:

journalctl --user -u halyard-daemon -f

Symptom	Likely cause
"No usable secret service found" at startup	gnome-keyring is not running, or the login keyring is locked. Unlock it and restart the daemon.
The app sits on "connecting"	Start the daemon with systemctl --user start halyard-daemon.
A pair shows an error and stalls	The message is verbatim from the daemon. Failed items are retried on the next cycle; sync does not stop for one bad file.
Notifications never appear	GNOME only shows them once the .desktop file is installed in XDG_DATA_DIRS, which install.sh does.
Nothing syncs after sign-in	Check the pair is enabled and not globally paused (GetStatus shows both).

You can safely delete ~/.cache/halyard/. Do not delete ~/.local/share/halyard/sync.sqlite as routine troubleshooting. It records the last state shared by both sides.

Uninstall

systemctl --user disable --now halyard-daemon.service
rm -f ~/.config/systemd/user/halyard-daemon.service \
      ~/.local/share/dbus-1/services/io.github.votton.Halyard.Daemon.service \
      ~/.local/bin/halyard \
      ~/.local/share/applications/io.github.votton.Halyard.desktop
rm -rf ~/.local/lib/halyard ~/.local/share/doc/halyard
systemctl --user daemon-reload

# Optional: remove sync state, cache, and logs
rm -rf ~/.local/share/halyard ~/.cache/halyard ~/.local/state/halyard

Your synced files are left alone. Remove the keyring entry "Halyard — Proton Drive session" in Passwords and Keys to drop the stored session.

Limitations

• Linux and GNOME only
• One account
• No resumable transfers; interrupted uploads restart
• Symlinks are skipped
• Shared-with-me folders are untested

Verification status

This is alpha software. It has more than a month of real-world use across multi-gigabyte pairs with thousands of documents, photos, videos, configuration files, and nested folders. Uploads, downloads, moves, deletions, conflicts, and session restore have all been exercised against a real account. Recovery from a network failure during a transfer is still unverified. Keep a backup and start with non-critical files.

Licence

Halyard is licensed under the MIT License. It bundles Proton Drive SDK code under its own MIT licence; see the third-party notices. Use of Proton's hosted services remains subject to Proton's terms.