arca
Edit here. Pick up there.
Edit a document on your laptop or import a file from your phone. Changes travel through your hub to the other devices that keep that folder. Each device chooses its own folders.
Your personal drive, on your own machines.
Many devices.
One space.
Your laptop, tablet and phone each have a place in your day. Arca keeps the folders you choose in sync across them, with complete local copies and a hub you run yourself.
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.
Work on your laptop. Take documents on your tablet. Save a file from your phone. Your shared folders connect those moments without sending yourself another attachment.
Offline is a normal day.
Once a folder has finished syncing, its files are on your device. Open them without a connection. Offline edits wait until Arca can reach your hub and sync again.
A way back.
Browse retained revisions and restore an earlier version. When edits conflict, Arca keeps both versions for you to review. Your hub holds the history.
02 / Keep the storage in your hands
Your files need a home.
You can provide it.
Keeping devices in sync doesn’t have to mean putting your files in a provider’s storage account. With Arca, you supply the storage, choose the devices and decide which folders each one keeps.
Your capacity comes from your own disks. Your files remain ordinary files. Arca needs no external account and runs without a public relay or telemetry.
You also run the hub and look after its storage and backups. Devices need to reach it to exchange changes; completed local copies remain usable while it’s offline.
03 / Bring your devices together
A home for your files.
A copy where you need 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
Make room for what matters.
Select whole folders on each device. Open them in Finder, edit in your favorite app, or share a file into Arca from your phone.
04 / Start with the devices you own
A home for your files.
Room for your devices.
Get the Mac app, set up your hub, and connect the devices you want to keep in sync.
DesktopStart here
Arca for desktop
Your folders in Finder, with sync and history close at hand.
Download for macOSApple Silicon · Version 0.3.8
Also for your desktop
Arca for mobile
Keep selected folders offline. Share files in, and take them with you.
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 hub
Arca with Docker
A home for your shared folders and history. Run the hub on an always-on computer or a compatible NAS, and manage it in your browser.
Linux · macOS and Windows with Docker Desktop
Linux
containers · amd64 / arm64
docker pull satoshiltd/arca:0.3.8Get the Docker imageMount persistent storage for your files and history.
About Docker Desktop ↗
Release notes · 0.3.8
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:0.3.8 and ghcr.io/satoshi-ltd/arca:0.3.8 (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.
A few good questions
Know what you’re keeping.
Where do my files live?
On your hub and the devices where you select their folders. Desktop uses local paths you choose; mobile keeps complete copies in app storage. Arca has no external account, public relay or telemetry.
Is sync the same as a backup?
No. File deletions synchronize too. Retained history lets you restore earlier content, while an optional full hub backup on a desktop or server is separate from working copies. Phones cannot be hubs or full-backup devices.
What happens when two devices edit the same file?
Arca preserves conflicting versions separately. Review them and choose which content to keep; restoring creates a new revision rather than rewriting the past.
Can I use it away from home?
Yes, when your device can reach the hub over your own private network, for example with Tailscale. Offline copies remain available without a connection. Arca does not provide a hosted relay.
Does a new release update my apps automatically?
This page offers the current published installers. Download and install a new version to update your apps; server deployments are managed by you.