How to Host a Sven Co-op Dedicated Server (SteamCMD App 276060)

To host a Sven Co-op server, download the free dedicated server with SteamCMD (app 276060), start it with SvenDS -console -port 27015 +maxplayers 12 +map svencoop1 on Windows or ./svends_run with the same arguments on Linux, and open port 27015 UDP (plus TCP for RCON) on your router. Set the name, password and region in svencoop/server.cfg, and friends join by typing connect your.ip:27015 in the console.

Sven Co-op is old and small, and that works in your favor. It runs on a modified GoldSrc engine, so the server needs very little power, and the game itself is free on Steam, so nobody in your group has to buy anything to join.

What you need before you start

• A PC or Linux box that can stay on while people play. The server itself is light: a friend group on the bundled campaigns fits in about 2 GB of RAM.
• Around 10 GB of disk space for the server files plus any map packs you add later.
• Access to your router for port forwarding, and a public IP address. If your ISP puts you behind carrier grade NAT, port forwarding will not work at all; see how to tell if you are behind CGNAT.
• Every player needs Sven Co-op from Steam. It is free.

Step 1: Download the server with SteamCMD

The dedicated server is a separate Steam app from the game. Install SteamCMD and run:

steamcmd +login anonymous +force_install_dir "C:\SvenDS" +app_update 276060 validate +exit

On Linux, swap the folder for something like /home/sven/server. Anonymous login is fine, so you do not need a Steam account that owns anything. Run the same line again after every game update, because players on a newer client cannot join an older server. If SteamCMD is new to you, our SteamCMD on Linux guide covers the install.

Linux note: the Sven Co-op server is a 32 bit program. On a 64 bit Debian or Ubuntu system, install the 32 bit runtime first (lib32gcc-s1 and lib32stdc++6), or the server exits right after launch.

Step 2: Start it once

The official manual lists two launchers: SvenDS.exe on Windows and svends_run on Linux. Without arguments, the Windows version opens a small graphical window. With -console you get a plain console, which is what you want for a server that stays up.

Windows, from the server folder:

SvenDS -console -port 27015 +maxplayers 12 +map svencoop1 +log on

Linux:

./svends_run -console -port 27015 +maxplayers 12 +map svencoop1 +ip 0.0.0.0 -strictportbind

What each part does:

Leave it running for a minute, watch for errors, then type quit to stop it.

Step 3: Edit server.cfg

The main config is svencoop/server.cfg. It runs when the server starts and again on map changes. The lines most groups touch:

hostname "Thursday Night Co-op"
sv_password "crowbar"
rcon_password "a-long-random-string"
sv_region 0
mp_timelimit 60
mp_respawndelay 6
mp_npckill 1
mp_dropweapons 1
skill 3

• hostname: the name in the server browser.
• sv_password: leave it empty ("") for a public server.
• rcon_password: lets you run console commands from inside the game. Make it long.
• sv_region: where the server shows in the Steam browser. 0 is US east, 1 US west, 2 South America, 3 Europe, 4 Asia, 5 Australia, 6 Middle East, 7 Africa, 255 worldwide. Set -1 to hide it from the list entirely, which is handy for a private group that joins by IP.
• mp_timelimit: minutes before the map changes on its own. Long campaign maps need more than the default if your group is slow.
• mp_npckill 1: controls what happens when someone shoots a friendly NPC like a scientist.
• skill: difficulty from 0 to 3.

The full list of variables is in the official server configuration manual. Two other files in the same folder matter early: mapcycle.txt (map order) and admins.txt (who gets admin). Changes in server.cfg apply on the next map.

Step 4: Open the ports

From the Sven Co-op manual:

Forward 27015 UDP and TCP to the server PC's local IP and allow the server through your firewall. Our port forwarding guide walks through the router side, and Windows Firewall rules for a game server covers the PC side.

Step 5: Pick the maps to run

Out of the box the server has the Sven Co-op stock maps plus co-op versions of Half-Life, Opposing Force, Blue Shift and They Hunger. svencoop1 is a safe first map. For a Half-Life campaign night, start on hl_c01_a1 and the maps chain on from there.

Community maps from the Sven Co-op map database go into a separate folder called svencoop_addon, never straight into svencoop. The manual is clear on this because it keeps updates from overwriting or clashing with your extras. Adding packs, building a map cycle and setting up fast downloads is its own job, covered in how to add custom maps to a Sven Co-op server.

Step 6: Get your friends in

1. Everyone installs Sven Co-op from Steam.
2. Turn on the developer console under Options > Keyboard > Advanced.
3. Press ~ and type connect 203.0.113.10:27015 with your public IP.
4. If you set sv_password, they type password crowbar first, or enter it when asked.

Once they have joined once, they can add the server to their Steam favorites and use the in game browser. If you set sv_region to -1, the IP route is the only way in, which is the point.

Common first day problems

Server closes right after starting. Usually the start map is missing (typo, or a custom map not uploaded yet) or, on Linux, the 32 bit libraries are not installed. Read the last lines of the console.

Friends time out on connect. Port 27015 UDP is not forwarded, the firewall is blocking the server, or you are behind CGNAT. Test from outside your network, since connecting to your own public IP from inside often fails even when everything is right.

Version errors after a game update. Run the SteamCMD app_update 276060 validate line again and restart.

Players stuck downloading a big custom map. The game sends files slowly. Set up sv_downloadurl or send your regulars the map pack ahead of time.

The easy option

If keeping a PC on all week for co-op nights is the part you do not want, a Sven Co-op server from GamezServers skips steps 1, 2 and 4. It is live about a minute after you pay with its own address, and the Server Name, Password, Region, Max Players and Default Map are fields in the control panel. You still get server.cfg, mapcycle.txt and svencoop_addon in the file manager or over SFTP, a live console for map changes, and one click backups. The 2 GB plan covers the bundled campaigns, and your group can split the bill with each person paying their share.

FAQ

Is the Sven Co-op dedicated server free?

Yes. The server (app 276060) downloads with an anonymous SteamCMD login, and the game itself is free on Steam, so nobody needs to buy anything.

What port does Sven Co-op use?

27015 by default, UDP for game traffic and TCP for RCON. VAC also uses UDP 26900. You can change the game port with -port on the launch line.

How many players can a Sven Co-op server hold?

Up to 32 with +maxplayers. The default is 12, and many maps get crowded past that, so match the slot count to the maps you run.

Can I run the server on the same PC I play on?

Yes, the server is light enough. Start it with -console so it does not open a second window, and connect to it with connect 127.0.0.1:27015 from your game.

Why is my server not in the Steam server list?

Check sv_region. A value of -1 hides it on purpose. If it is set to a region, make sure port 27015 UDP is forwarded, then give the master server a few minutes after a restart.