Questions

Yes. That's the trade: nothing is stored by anyone else, so something of yours has to hold it. Anything that runs Docker will do — a NAS, an unRAID box, a mini PC, a Pi. It doesn't need to be fast; it needs to be on.

Yes. Install Tailscale on your locker and on your machines — it's free for personal use and takes about five minutes — and your Deck syncs from anywhere in the world as though it were sat on your sofa. WireGuard, Netbird, ZeroTier or a Cloudflare Tunnel all work the same way. Point the agent at the tunnel address and there's nothing else to configure.

Nothing needs opening up on your router either way: the agents only ever make outgoing connections, so there's no port forward and no inbound hole in your firewall.

And if you're somewhere with no connection at all, the Deck just keeps playing. Saves queue up on the device and sync themselves the moment you're back in reach.

Correct, and this is the part worth understanding. There's no relay in the middle and no service brokering your connection — your agents talk to your locker and to nothing else. Over a tunnel like Tailscale, that traffic is encrypted end to end between your own devices, and there is no third party anywhere in the path who could read a save even if they wanted to.

No. It reads your Steam library, but it also picks up non-Steam games you've added to Steam, and games staged in Heroic Games Launcher — Epic, GOG, Amazon and sideloaded titles. Anything else, you can point it at the save folder by hand.

Not yet. RetroArch, Dolphin, PCSX2 and the rest keep saves in their own layouts that nothing in the automatic detection understands today. It's on the list.

Not yet. Windows and Linux, including the Steam Deck.

While a game is running, that machine holds it — the others get told before they can stomp on it. If two machines change the same save anyway (you were offline, say), SaveLocker notices that the saves have diverged, flags it as a conflict, and hands you both options in the console. It won't pick for you, and it won't quietly throw one away.

Yes. Every sync is kept as a version — ten per game by default, and you can change that. Roll back to any of them from the console.

Ordinary zip files on your own disk, in a folder you chose. Nothing proprietary — if you ever bin SaveLocker, your saves are still sitting right there. The console is behind an admin password, the agents authenticate with a per-machine key you never see, and the server takes a backup of its database nightly.

It's free for personal use and the source is on GitHub. It's licensed under PolyForm Noncommercial, which means you can use it, read it and modify it for yourself — you just can't sell it or build a commercial product on it. There's no paid tier, no account and no telemetry.

Because it isn't code-signed yet — a certificate costs money and we haven't bought one. SmartScreen throws that warning at every unsigned installer regardless of what's in it. More info → Run anyway. If you'd rather not, you can build it yourself from source.

No. It's an independent project with no connection to Valve.

On the Deck, run savelocker doctor — it diagnoses the whole chain and names the broken link. In the console, the Help tab has the reference material and the machine health page will show you which agent has stopped reporting. Beyond that, open an issue.