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Project Zomboid

This guide walks you through the process of deploying, managing, and connecting to a Project Zomboid (Build 41) Dedicated Server using FluxCloud. Whether you're starting a fresh outbreak in Knox Country or migrating an existing world, this page provides step-by-step instructions and key details for a seamless experience.

The FluxCloud Project Zomboid template is built on the danixu86/project-zomboid-dedicated-server image, which handles SteamCMD installation, automatic configuration from environment variables, and Steam Workshop mod support.

For more information on Project Zomboid visit: https://projectzomboid.com. For the server image documentation, see: https://github.com/Danixu/project-zomboid-server-docker.

How To Install a Project Zomboid Server​

Steps​

  1. Access FluxCloud
  1. Find the Project Zomboid Server
  • Navigate to the Marketplace → Games tab, then locate the Project Zomboid tile and click View Details.
  1. Select Server Configuration
  • Choose your preferred configuration based on expected player count:
    • 8 Slots — 4GB RAM, 2 CPU cores, 15GB SSD. Ideal for a small group of friends.
    • 16 Slots — 6GB RAM, 2.5 CPU cores, 20GB SSD. Balanced for medium communities.
    • 32 Slots — 10GB RAM, 4 CPU cores, 30GB SSD. Recommended for large groups or heavily modded servers.
  • Click Install Now to continue.
  1. Provide Server Configuration Values
  • Fill in the required fields:
    • SERVERNAME — the internal server identifier (no spaces or special characters). All of your server's files — config, world save, player database — are named after this value. Changing it later effectively creates a brand-new world, so pick it carefully.
    • DISPLAYNAME — the name shown in the in-game public server browser. This can contain spaces and can be changed later.
    • SERVERPRESET — the game difficulty preset used to generate your world's sandbox settings: Apocalypse (default), Beginner, Builder, FirstWeek, SixMonthsLater, Survival, or Survivor. The preset is applied only on first launch — choose before deploying, as changing it afterwards requires resetting your sandbox settings.
    • ADMINPASSWORD — the password for the server's admin account. Required — the server will not start without it. Use a strong password.
  • Optionally fill in:
    • PASSWORD — a join password players must enter to connect. Leave empty for no join password. (Applied after the first restart — see below.)
  • Optionally expand Advanced Settings to configure:
    • ADMINUSERNAME — the admin account username. Choose from admin (default), serveradmin, or owner.
  1. Choose Subscription
  • Select your desired subscription duration.
  • Agree to the Terms of Use and Privacy Policy, and click the blue Continue arrow at the bottom.
  1. Deployment Location
  • Configure whether you want your Project Zomboid server to deploy in specific geographic regions:
    • Global (Recommended): No geographic restrictions for best availability.
    • Custom: Restrict by continent or country.
  • Click the blue Continue arrow to proceed.
  1. Email Notifications
  • Optionally enter your email address to receive notifications about your game server, including:
    • When your application finishes launching.
    • When the primary server changes.
    • When your app expiration date is approaching.
  1. Launching the Application
  • Your application must be signed and registered on the Flux network.
    1. Click Sign and Register.
    2. Sign the message using the pop-up.
      • If you logged in via Google or Email, this step is completed automatically.
  1. Complete Payment
  • Choose your payment method:
    • Fiat: Stripe or PayPal
    • Crypto: FLUX coin (5% discount)
  • Payment is monitored automatically. Once confirmed, your application will be deployed, and a blue Manage button will appear—directing you to your application's management panel.

⚠️ Important: FLUX Payments

FLUX payments are only accepted via the FLUX Mainnet, not through any of our EVM tokens.

We ALSO strongly recommend not sending FLUX payments from exchanges, as:

  • Transactions or withdrawals may not complete within the required 30-minute window.
  • Many exchanges do not support adding a MEMO, which is required for proper payment processing.

First Launch — Allow Time for the Server to Download​

When your Project Zomboid server starts for the very first time, the container downloads the full dedicated server files from Steam via SteamCMD and generates your world configuration before it can accept connections. This is normal and only happens on first launch (or after a major game update).

  • Expect the initial download and setup to take several minutes (typically 5–15 minutes depending on network conditions and node performance).
  • You can follow progress by opening Applications → Management → Logs in FluxCloud and watching the container output. Once you see *** SERVER STARTED *** / Server Steam ID messages, the server is up.
  • Subsequent restarts are much faster — the server files are cached on the persistent volume.

Required: Restart Once After First Launch​

The server generates its configuration file (<SERVERNAME>.ini) during the first boot. Because that file does not exist yet when the container applies your settings, three of your values cannot be written on the very first launch:

  • The join password (PASSWORD)
  • The public server browser listing and your DISPLAYNAME

These are applied automatically on the next start. After your server finishes its first launch:

  1. Go to Applications → Management on cloud.runonflux.com and select your Project Zomboid app.
  2. Click the Settings icon, open the Control tab, select Local, and click Restart Application.

After this one restart, your server name appears in the in-game browser and the join password (if you set one) is enforced. You do not need to repeat this on later restarts.

⚠️ Until this restart is done, your server is joinable without a password and is not listed in the public server browser.

Finding the IP of Your Game Server​

Flux runs on a decentralized network, meaning your application is deployed across multiple instances.
For game servers, a Primary/Standby setup is used — your game runs on the primary instance, while the other instance is on standby for redundancy.

To find your server's primary IP address:

  1. Visit cloud.runonflux.com and log in.
  2. Go to Applications → Management.
  3. Click the Settings icon on your Project Zomboid Server.
  4. Open the Instances tab.
    • The Primary IP address is shown here.
    • You can also view geolocation details for all instances.

To connect to your server from the Project Zomboid client:

  1. Launch Project Zomboid and click Join.
  2. Open the Favorites tab and add your server:
    • IP: your Primary IP address
    • Port: 36261
  3. Alternatively, find your server in the Internet tab of the server browser by searching for your DISPLAYNAME (available after the post-deploy restart), or join through a Steam friend invite.
  4. Enter an Account Username and Account Password of your choice — Project Zomboid creates a per-server character account for each player on first join. Remember these credentials; you'll need them to log back in as the same character.
  5. If you configured a join password, enter it in the Server Password field.

💡 Tip: Your server uses UDP ports 36261 (main game port) and 36262 (direct-connection port). Both are exposed automatically by FluxCloud — players only ever need to enter 36261.

Connecting via Domain Instead of IP​

Every FluxCloud Marketplace game server is also reachable through its application domain. Flux's load balancer forwards UDP traffic over DNS and is already configured with the correct game port, so you keep a stable address even when the primary instance changes due to failover.

  • Find your app domain under Applications → Management → Information.

  • Use it in the IP field of the Favorites tab in place of the IP address. The game port is already baked into the domain's DNS routing, so you do not need to append :36261:

    your-app-domain.app.runonflux.io

Using the domain means you never have to update your saved server entry when the primary switches.

Becoming Admin In-Game​

Your server has a built-in admin account, created from the ADMINUSERNAME and ADMINPASSWORD you provided at deployment.

  1. Join your server and, at the login screen, enter your ADMINUSERNAME (default admin) as the Account Username and your ADMINPASSWORD as the Account Password.
  2. Once in-game, an Admin icon appears on the left side of the screen — click it to open the Admin Panel, where you can edit server options, manage players, spawn items and vehicles, and teleport.
  3. You can also run admin commands from the chat (press T), for example:
    • /setaccesslevel "PlayerName" admin — promote another player (levels: admin, moderator, overseer, gamemaster, observer).
    • /players — list connected players.
    • /kickuser "PlayerName" -r "reason" / /banuser "PlayerName" -r "reason" — moderation.
    • /servermsg "Server restarting in 5 minutes" — broadcast a message.
    • /save — force a world save.
    • /help — list all available commands.

⚠️ Only share the admin credentials with people you trust — the admin account has full control over the server and the world.

Adjusting Server Settings​

Changing deployment values (environment variables)​

The values you provided at deployment (DISPLAYNAME, PASSWORD, ADMINPASSWORD, etc.) can be changed later:

  1. Go to Applications → Management on cloud.runonflux.com and select your Project Zomboid app.
  2. Click the Settings icon and open the Specifications tab, then click Update.
  3. Navigate to the Component tab — here you will find the environment variables. Edit the values you want to change.
  4. Click Review in the top-right corner to review your changes.
  5. Confirm and sign the update — the update is registered on the network free of charge.
  6. Allow several minutes for the update to propagate across the Flux network. Your server will restart with the new settings.

⚠️ Important: Do not modify the pre-set PORT, PUBLIC, or MEMORY variables. In particular, PORT intentionally contains 36261 -udpport 36262 to configure both game ports natively — changing it will break connectivity. Also avoid changing SERVERNAME unless you intend to start a brand-new world (see FAQ).

Editing the server configuration file​

All other server options live in the server's .ini file on the persistent volume, named after your SERVERNAME:

  1. Click the Settings icon, open the Secure Shell tab and scroll to Volume Browser.

  2. Open the file:

    /home/steam/Zomboid/Server/<SERVERNAME>.ini

  3. Common settings you may want to change:

    • MaxPlayers= — the player cap. The game's default is 32; set this to match your plan (e.g. 8 or 16) to keep performance consistent.
    • PVP= — enable/disable player-versus-player (default true).
    • PauseEmpty= — pause the world simulation when no players are online (default true).
    • Open= — set to false to switch the server to whitelist mode (players must be pre-created with /adduser).
    • PublicDescription= — the description shown in the server browser.

  4. Save your changes, then open the Control tab, select Local, and click Restart Application so the new settings take effect.

⚠️ Important: Some .ini values (Password, Public, PublicName, Mods, WorkshopItems) are re-applied from environment variables on every start and will be overwritten at boot. Change those through the Specifications → Component update flow instead.

Tuning gameplay difficulty (Sandbox settings)​

Zombie population and behaviour, loot rarity, day length, XP multipliers, water/electricity shutoff and similar gameplay rules are stored separately, in:

/home/steam/Zomboid/Server/<SERVERNAME>_SandboxVars.lua

This file is generated from your SERVERPRESET on first launch. You can fine-tune individual values via the Volume Browser, save, and restart the application to apply.

⚠️ Important: Invalid configuration values can prevent the server from starting. Back up any file before editing and revert if the server fails to boot. Note that many sandbox settings (like zombie population) only fully affect newly explored map areas — already-visited areas keep their existing state.

Managing the World Save​

Your world data lives on the persistent volume, named after your SERVERNAME:

PathContents
/home/steam/Zomboid/Saves/Multiplayer/<SERVERNAME>/The world save — map state, buildings, loot, player positions
/home/steam/Zomboid/db/<SERVERNAME>.dbThe player database — accounts, whitelist, admin access levels
/home/steam/Zomboid/Server/Server configuration files

Download a backup​

Use the Volume Browser to download the world save folder and the .db file before risky changes (mod installs, game updates, sandbox edits). Saved files can be re-uploaded later using the procedure below.

Roll back to a previous backup / Upload an existing world​

Simply dropping save files onto a running server is unreliable: the server holds the world files open and writes autosaves on a timer, so a copy that overlaps with an autosave can leave the world in a half-written state. Pause the container first:

  1. Open Applications → Management, select your Project Zomboid app, and switch to Control → Local → Pause Container. Pausing stops the server from writing to the world while you upload.

  2. Open the Volume Browser and upload your world folder into:

    /home/steam/Zomboid/Saves/Multiplayer/<SERVERNAME>/

    Also upload the matching player database to /home/steam/Zomboid/db/<SERVERNAME>.db if you want to keep player accounts and characters.

  3. Return to Control → Local → Restart Container. The server starts with the uploaded world.

💡 Tip: When migrating a world from another host, the save folder and database must be renamed to match your SERVERNAME exactly — Project Zomboid finds them by name.

Installing Mods (Steam Workshop)​

The server image has built-in support for Steam Workshop mods through two environment variables. Mods are downloaded by the server itself — no manual file uploads required.

  1. Find the mods you want on the Project Zomboid Steam Workshop. For each mod, note from its Workshop page:

    • The Workshop ID (the number at the end of the page URL).
    • The Mod ID (listed in the mod's description).

  2. In FluxCloud, open your application settings, go to the Specifications tab, click Update, and open the Component tab.

  3. Add two new environment variables (semicolon-separated lists, no spaces):

    WORKSHOP_IDS=2169435993;2392709985
    MOD_IDS=tsarslib;BetterSorting

  4. Click Review, confirm, and sign the update. Allow several minutes for the change to propagate; the server restarts automatically.

  5. Mods are downloaded on the next start and activated on the start after that — map mods can take one additional restart while the server detects and registers the new map. If mods don't appear active immediately, restart the application once more from Control → Local → Restart Application.

⚠️ Important: All players connecting to a modded server must subscribe to the same Workshop mods locally. Allow extra startup time after adding large mods — they are downloaded through Steam on the server's next boot. Mods may break after a game update; remove a problematic mod from both lists to disable it.

Frequently Asked Questions​

Why can't I see my server in the in-game browser, and why is my join password not working?​

Both are applied on the second server start. The configuration file the password and browser listing are written into is only generated during the first launch, so they cannot take effect until the next boot. Restart your application once from Control → Local → Restart Application after the first deployment — see Required: Restart Once After First Launch.

What ports does Project Zomboid use?​

The server uses UDP port 36261 as the main game port and UDP port 36262 as the direct-connection port. FluxCloud exposes both automatically. When connecting by IP, players enter port 36261; when connecting via the app domain, the port is resolved by DNS and does not need to be specified.

Players are asked for a username and password when joining — what are these?​

That's normal Project Zomboid behaviour, not a Flux setting. Each player creates a personal account (username + password) on your server when they first join; it stores their character. These accounts live in the server's player database (db/<SERVERNAME>.db) and are unrelated to the server join password, which is the shared PASSWORD you optionally set at deployment.

Can I change the difficulty preset after deployment?​

The SERVERPRESET only generates your sandbox settings file on the first launch — changing the variable later has no effect on an existing world. To adjust difficulty afterwards, edit individual values in /home/steam/Zomboid/Server/<SERVERNAME>_SandboxVars.lua via the Volume Browser, or use the in-game Admin Panel → Sandbox Options as the admin account. Keep in mind many settings only affect newly explored areas.

What happens if I change SERVERNAME?​

Project Zomboid names every server file — configuration, sandbox settings, world save, and player database — after the SERVERNAME. Changing it makes the server generate a fresh world with default settings under the new name. Your old world is not deleted; reverting SERVERNAME to the previous value brings it back.

What happens if the primary server goes down?​

If your current primary server becomes unavailable or experiences downtime, the standby instance automatically takes over as the new primary after a short delay. Your world save, player database, and configuration are preserved on the persistent volume, so the game resumes where you left off once the switch is complete. You can check which instance is currently the primary from your application's management panel under the Instances tab.

💡 Tip: If you connect via the app domain (your-app-domain.app.runonflux.io, no port suffix) instead of the raw IP, your client will keep reaching the correct primary automatically after a failover.

How can I update my game server to the latest version?​

The server checks for updates from Steam during startup. To update immediately, open Applications → Management, select your Project Zomboid server, go to the Control tab, choose Local, and click Restart Application. The latest Build 41 dedicated server files are pulled on the next boot.

The server feels sluggish with many players — what can I do?​

  • Set MaxPlayers= in the .ini to match the plan you purchased (8/16/32) instead of leaving the game default of 32 on a smaller plan.
  • Keep PauseEmpty=true so the simulation rests while nobody is online.
  • Heavy mod lists (especially map mods) increase RAM usage significantly — consider upgrading to a larger configuration if you run many mods.