How to host a Foundry server (2026)

Short answer. You can host a Foundry server yourself for free: install "FOUNDRY: Dedicated Server" (Steam app 2915550), create an app.cfg next to FoundryDedicatedServer.exe and open port 3724 on your firewall and router. Or rent a Foundry server and skip the networking.

Players join with Multiplayer, then IP Direct Connect, and type your server's IP address and port. If you set the server to public, it also shows in the Steam server browser.

Checked on 5 November 2026, when the newest stable build announced on Steam was Update 4 Hotfix #2. Update 5 was only on the experimental branch.

This guide uses two sources: the developer's own dedicated server page and what we run on every Foundry server we host. Where the two differ, it says so. To skip to the rental route, go to Option 2.

What you need

• The server software: "FOUNDRY: Dedicated Server", Steam app 2915550. The game itself is app 983870, and you do not need to own it to run the server. In the Steam client, open the Library dropdown and turn on Tools to see the server.
• A machine that stays on: a spare PC, a home server or a cloud virtual machine. The developer's page describes Windows only. We run the Windows server under Wine on Linux, and the Linux steps below are the ones we use.
• RAM and CPU: the developer's page does not list system requirements, so treat any figure you read elsewhere as an estimate.
• Network: port 3724 (the default game port) open on the firewall and forwarded on your router. The developer's page does not say whether it is TCP or UDP, so allow both. The Steam server browser uses a query port, 27015 by default, only if the server is public.
• The same version as your players: the server version must match the game version.

Option 1: host it yourself

On Windows (the developer's route)

1. Install the server from the Tools section of your Steam library, or with SteamCMD.
2. Create app.cfg in the same folder as FoundryDedicatedServer.exe. To find the folder, open the server's Properties in Steam, go to Installed Files and choose Browse. A starting file:

   server_name=My Foundry server
   server_password=changeme
   server_world_name=MyFactory
   server_max_players=16
   server_is_public=false
   pause_server_when_empty=true
   autosave_interval=300
   server_port=3724
   server_query_port=27015

   The developer's page also lists server_persistent_data_override_folder, a custom folder for logs and saves meant for providers who run several servers on one machine.
3. Start it from Steam or with FoundryDedicatedServerLauncher.bat in the server folder.

On Linux (the way we run it)

1. Install SteamCMD and the libraries it needs, plus Wine and Xvfb (the wine and xvfb packages on Debian and Ubuntu). Steam lists the server for Windows only, so Wine runs it.
2. Download the Windows build of the server. Our install forces the Windows platform and installs app 2915550 into the server folder:

   ./steamcmd.sh +force_install_dir /home/foundry/server +login anonymous +@sSteamCmdForcePlatformType windows +app_update 2915550 validate +quit

3. Check the install. SteamCMD sometimes reports success and leaves an empty folder. If the steamapps folder holds no appmanifest_2915550.acf file, or FoundryDedicatedServer.exe is missing, run the command again.
4. Copy the Steam client libraries where we put them: steamclient.so from SteamCMD's linux32 folder into .steam/sdk32 and from linux64 into .steam/sdk64, both under the user's home folder.
5. Write app.cfg in the server folder with the keys from the Windows example.
6. Run the server under Wine with a virtual display, which is how our servers start it:

   xvfb-run wine ./FoundryDedicatedServer.exe -log

   Before each start, our servers also install Wine Mono (the wine-mono MSI from its GitHub releases) into the Wine prefix. The server is ready when the log prints Dedicated server is now running!. Run it under a service manager such as systemd so it restarts after a crash.

Open the ports and join

• Game: allow port 3724 (for example sudo ufw allow 3724) and forward it on your router.
• Steam browser: only with server_is_public=true, and it uses the query port 27015.
• Join: in the game, choose Multiplayer, then IP Direct Connect, and enter the IP address and port.
• Update: run the download command again. The developer's page says that if app_update does not update the server correctly, you should delete the server and reinstall it.

Option 2: host it on PlayNHost

Renting removes the install, Wine, the ports and the update routine. You still choose a name, a password and your world.

1. Pick a plan. Open the Foundry server hosting page and compare the plans: MACHINERY (16 players) and SCIENCE (24 players) at the time of writing. Press Create Server on MACHINERY or Customize Plan on SCIENCE and finish the order. Prices change, so check them on that page.
2. Wait for the install. The server appears in the panel. Its Console prints Dedicated server is now running! when it is ready.
3. Name it. On the Settings tab, under Game Settings, set the Server Name, the Server World Name and a Server Password. Then restart. See How to change your Foundry server name, password and slots.
4. Choose how it is listed. Server Public controls the Steam server browser. Pause Server When Empty and Autosave Interval are on the same page.
5. Invite your players. Give them your server's address and port for IP Direct Connect. See How to connect to your Foundry server.

What the panel does for you:

• Your ports are assigned and open from the start. The panel writes the game port, query port, name, password, world name, player cap, public flag, autosave interval, pause setting and save folder into App.cfg at every start, so you change them in the panel, not in the file.
• The install checks for an app manifest after each SteamCMD run and tries up to three times before it reports a failed install.
• Steam Workshop mods install for you. Paste the item ids, separated by commas, into Steam Workshop mods under Settings. The install downloads them with an anonymous login, so nobody needs to own the game, and it deletes any old modList.json; in our tests the server then wrote a new list with every mod it found switched on. The ids are read while the server installs, so use Reinstall to apply on the Modding page to apply a change. Everyone joining needs the same mods on their own game.
• Worlds live in serverfiles/save under Files, named after the world. A new Server World Name starts a fresh world without deleting the old one. See How to manage worlds and backups on your Foundry server.

Self-hosting or renting: an honest comparison

• Cost: the server software is free. Self-hosting costs power, hardware and bandwidth, or a cloud machine. Renting is a monthly fee set by the plan.
• Uptime: a home server is only up while your PC, power and internet are. A rented server runs on the host's hardware.
• Exposure: at home, players connect to your public IP address and you look after the firewall and router. A rented server keeps your home IP out of it.
• Setup: the developer's route on Windows is short. On Linux you also need Wine, a virtual display and the SteamCMD check above. Renting needs a name, a password and a world name.
• Control: self-hosting gives you every file. On our servers you change settings in the panel and still have the Files tab.

Ready to skip the setup? See the Foundry server plans. Already have a server and players cannot join? Read Foundry server world is missing or players cannot join.