arca
Edit here. Pick up there.
Edit on your laptop or save a file from your phone. Changes travel through your hub to every device that keeps that folder.
Your personal drive, on your own machines.
Many devices.
One space.
Keep documents in sync and bring photos together on a computer you control. That’s your hub. Choose which folders each device keeps, with complete local copies ready to use offline.
Apple Silicon · macOS
Your storage. No cloud storage account
required.
Your devices, working together
Home serverYour hub
EverydayAll the things worth keeping.
✓ Up to date
Projects12 files›
Documents28 files›
Adventures16 files›
Phone & tabletYour selected folders, offline
✓
Choose what belongs on each device.
Complete local copiesSync in both directionsRestore earlier versionsA hub you control
01 / One person. More than one device.
Move between devices.
Keep your files with you.
Keep working in the apps you already use. Arca carries folder changes between devices, so you can pick up where you left off without emailing yourself a copy.
Offline is a normal day.
Once a folder finishes syncing, its files are on your device. Open them offline. Your edits sync when the hub is reachable again.
A way back.
Changed your mind about an edit? Restore an earlier version from retained history. If edits conflict, Arca keeps both versions for you to review.
Your storage. On your terms.
Ordinary files on your own disks, with no external account, public relay or telemetry. You run the hub and look after its storage and backups.
02 / Bring your devices together
One hub.
Your devices around it.
One computer or server is your hub: it keeps your shared folders and their history. An always-on machine lets your devices sync without waiting for your laptop to wake up.
-
01
Choose your hub.
Run Arca on your computer or a server with Docker. Use the web app to manage the server and choose the folders to share.
-
02
Pair your devices.
Connect with a single-use pairing code. Use your local network, or your own private network such as Tailscale when you’re away.
-
03
Choose your folders.
Select whole folders independently on each device. Choose a local path on desktop; on mobile, Arca keeps the selected copies in app storage.
-
04
Link your photo albums.
Link a phone album to upload photos and videos to your hub, without a second Arca copy on your phone. Explore your gallery by date on desktop or the web.
-
05
Set your history retention.
Choose how long each folder retains earlier versions. Keep more history for ongoing work, or a shorter window for folders that change often.
03 / Start with the devices you own
Put Arca to work.
Start with a desktop or Docker hub, then add your phone, tablet and other computers.
DesktopStart here
Arca for desktop
Local folders in your file manager. Sync and history in Arca.
Download for macOSApple Silicon · Version 0.4.6
Also for your desktop
Arca for mobile
Take folders offline, save files from other apps and upload photo albums to your hub.
Mobile connects to your hub. Background sync follows your phone’s system limits.
Outside the store
Install directly, without Google Play or a store
account.
Your server
Arca with Docker
Install Arca with Docker on an always-on computer or a compatible NAS. Manage it in your browser and choose its role during setup: create a hub or join an existing one as a replica.
Linux · macOS and Windows with Docker Desktop
Linux
containers · amd64 / arm64
docker pull satoshiltd/arca:0.4.6Get the Docker imageUse persistent storage for your files and history, then open the
setup wizard in your browser on port 17831.
View Docker image ↗
Release notes · 0.4.6
Alpha direct downloads: macOS ad-hoc signed, not notarized (macOS may block downloaded apps); Windows unsigned. Linux and Windows need real installation qualification. Docker: satoshiltd/arca:0.4.6 and ghcr.io/satoshi-ltd/arca:0.4.6 (amd64/arm64; also tagged latest). No automatic updates or pilot deployment.
Arca is an early alpha. Installers and mobile workflows are still being qualified. macOS builds may be unnotarized and Windows builds unsigned; check the release’s installation status before installing. Keep an independent backup of important files.
Questions, answered
Before you get started.
Do I need a server to use Arca?
A dedicated server is optional. A computer you already own can be the hub, or you can run one with Docker. Phones and tablets connect to a hub; they cannot act as one.
Where do my files live?
On your hub and the devices where you select their folders. Desktop copies use local paths you choose; mobile copies live in app storage. Your own disks set the capacity.
Does every device need to keep everything?
No. Each device chooses whole folders independently. Selected folders download as complete files, ready for offline use. A linked phone album is different: it uploads without keeping a second Arca copy on that phone.
Does my hub have to stay on?
Only to exchange changes. Once a folder finishes syncing, its local files work offline. Edits wait until the hub is reachable again. An always-on hub makes syncing more convenient.
Can I use Arca away from home?
Yes, if your device can reach the hub, for example through your own private network with Tailscale. Arca provides no public relay and requires no external storage account.
How do photo albums work?
Link a phone album to a hub folder. Arca uploads new photos and videos; browse them by date on desktop or the web. Deleting from your phone’s gallery keeps uploaded files, and hub changes never write back to it.
Will my phone sync in the background?
Background work follows iOS and Android scheduling limits. Arca also resumes work when you open it. Keep the app open for a large first upload; background sync is not continuous.
Is sync a backup?
Sync also carries file deletions between ordinary folder copies. Retained history offers a way back, but keep an independent backup. Arca’s optional full hub backup runs on a desktop or server, separately from working copies.
Can I undo an edit or recover a deleted file?
Yes, while its history is retained. Restoring creates a new revision, leaving earlier history intact. Conflicting edits are kept as separate versions for you to review.
How do I update Arca?
Download and install a new version on your devices; update your server deployment separately. Check the release notes for any requirement to update the hub and replicas together.