How do I update my ATLAS server?

Stop the server, run SteamCMD again with the “app_update” command from the Updates section (with validate), then restart. Back up before big updates.

Do I need to own the game to host a ATLAS server?

No: the dedicated server downloads for free through SteamCMD with an anonymous login. Only players need the game.

What should I back up before an update?

The world save folder and the configuration folder (see the Backups section): copy them with the server stopped to get a consistent state.

How many servers does ATLAS need?

One process per cell of the grid defined in ServerGridEditor; a 1x1 grid needs only one, which is ideal for testing.

Install a ATLAS server: local, VPS, dedicated, ports

ATLAS (SteamCMD AppID 1006030) works as a “grid”: each cell of the map is a separate server process linked to the others. It is far more involved than a standard server. The information below comes from community guides and the official ServerGridEditor tool; several points are not officially documented.

Step-by-step installation

Check the OS and hardware (“Requirements” section).
Install SteamCMD, Steam's command-line tool.
Download the ATLAS server files with AppID 1006030 (anonymous login).
Start the server once to create its configuration files, then stop it cleanly.
Set the name, passwords, slots and rules with this site's tools.
Test the connection locally (localhost / 127.0.0.1) before opening the server to the Internet.
Open the ports in the system firewall, the host's firewall and, at home, on the router (NAT).
Set up a service (systemd or a Windows scheduled task) for automatic start and restart after a crash.
Schedule updates and backups, then restart regularly.
Add your server to game-rank.com so players can find it.

Requirements

OS: 64-bit Windows (the guides consulted only describe Windows). Community Docker images run a Linux server, which suggests a Linux build exists, but it is not officially documented here.
Hardware: one process per cell, so RAM and CPU grow with the grid size. No confirmed official minimum; start with a 1x1 grid to test.
Tools: ServerGridEditor (GrapeshotGames repository on GitHub) to define the grid and generate ServerGrid.json; according to the publisher's documentation, a Redis database links the cells (not re-verified here).
Accounts: none, SteamCMD anonymous login; only players need the game.

Local install (Windows)

Download the server with SteamCMD. In ServerGridEditor, open a template (Projects), set the name (Friendly Name) and password (Atlas Password) under Edit Project, then generate the grid. Next create one .bat file per cell with the “ATLAS launch command” tool. The first test is on 127.0.0.1 with a 1x1 grid.

cd C:\steamcmd
steamcmd.exe +force_install_dir C:\atlas-server +login anonymous +app_update 1006030 validate +quit

REM One start.bat per grid cell (see the ATLAS launch command tool):
REM start /high ShooterGame\Binaries\Win64\ShooterGameServer.exe "Ocean?ServerX=0?ServerY=0?AltSaveDirectoryName=A1?..." -server -log -NoBattlEye

Install on a Linux VPS / dedicated server (Ubuntu/Debian)

For a VPS or dedicated machine, a Windows Server is the safest bet: follow the local install. A native Linux install is not officially documented in the sources consulted; if you use a community Docker image, check its origin and read its code before running it.

# Windows Server (PowerShell, administrator)
New-Item -ItemType Directory C:\steamcmd, C:\atlas-server
Invoke-WebRequest https://steamcdn-a.akamaihd.net/client/installer/steamcmd.zip -OutFile C:\steamcmd\steamcmd.zip
Expand-Archive C:\steamcmd\steamcmd.zip C:\steamcmd
C:\steamcmd\steamcmd.exe +force_install_dir C:\atlas-server +login anonymous +app_update 1006030 validate +quit

Ports to open

Hosting provider (OVH, Hetzner, Scaleway…): open the same ports in the provider's firewall / security group on top of the system one. At home: forward (NAT) each port with the right UDP or TCP protocol to the machine's local IP, ideally a fixed one. Test from outside (a friend connecting, or a UDP port tester): a UDP port does not always answer a plain scan.

Each cell has its own ports: Port (game, UDP) and QueryPort (Steam query, UDP), e.g. 5761 and 57561 in the guide consulted.
Cells talk to each other (seamless): seamless data and RCON ports are set per cell in ServerGrid.json (values like 27000 for seamless and 5750/57550 for game/query appear in community images, as examples only).
Open all ports of all cells with the right protocol (UDP for game and query; check the seamless/RCON protocol in your ServerGrid.json) and keep them in sync with ServerGrid.json.

Windows firewall (netsh)

Adapt the ranges to your actual ports (example for a 1x1 grid using 5761 and 57561).

netsh advfirewall firewall add rule name="ATLAS UDP" dir=in action=allow protocol=UDP localport=5761,57561
REM Add the seamless/RCON ports from your ServerGrid.json with their protocol (TCP or UDP).

Automatic start and supervision

Create a Windows scheduled task at startup that runs each cell's .bat (or a single script calling them). No official systemd unit is documented for ATLAS.

schtasks /create /tn "ATLAS grid" /tr "C:\atlas-server\start-all.bat" /sc onstart /ru SYSTEM /rl HIGHEST

Updates

Stop all cells, run SteamCMD again with app_update 1006030 validate, then restart them together to avoid version mismatches between cells.

C:\steamcmd\steamcmd.exe +force_install_dir C:\atlas-server +login anonymous +app_update 1006030 validate +quit

Backups and scheduled restarts

Stop all cells then copy each instance's ShooterGame/Saved folder (AltSaveDirectoryName) plus ServerGrid.json and the Redis database if you use one. I could not confirm the exact save location in an official source: check on your install.

List and find your server

Once the server is reachable from the Internet, add it at https://game-rank.com/jeux/atlas: players discover it, vote and follow its ranking. Keep the query port open, otherwise the server will not show up in server lists.

Troubleshooting

The server is not in the list: the query port (UDP) is closed or the list takes several minutes to refresh; try adding it directly by IP:query port.
Cannot connect from the Internet but fine locally: missing system firewall rule, provider security group or port forwarding (NAT); check each rule's protocol (UDP/TCP).
The client reports a different version: the game was updated; stop the server, run SteamCMD with “app_update … validate” again, then restart.
Players get stuck crossing between cells: check that SeamlessIP, the seamless ports and the shared database match ServerGrid.json on every cell.
Two cells use the same ports or the same AltSaveDirectoryName: every cell needs its own ports and a unique save name.

Frequently asked questions

How do I update my ATLAS server?: Stop the server, run SteamCMD again with the “app_update” command from the Updates section (with validate), then restart. Back up before big updates.
Do I need to own the game to host a ATLAS server?: No: the dedicated server downloads for free through SteamCMD with an anonymous login. Only players need the game.
What should I back up before an update?: The world save folder and the configuration folder (see the Backups section): copy them with the server stopped to get a consistent state.
How many servers does ATLAS need?: One process per cell of the grid defined in ServerGridEditor; a 1x1 grid needs only one, which is ideal for testing.