Downloading and Hosting a Dedicated Server

Windows

SteamCMD

Dedicated servers are now downloaded using SteamCMD. This is a command line version of Steam.

You can download it from this page.

The first time you run it it will update and you will be left at a STEAM> console. You will want to log in. You can log into an anonymous account by typing:

Installing & Updating Garry's Mod Dedicated Server

If you want to specify a download folder then before you update enter this command:

This is known to cause problems when updating your server to a newer version. If your server fails to update, try not using the force_install_dir feature, or try reinstalling your server into another folder. You can also try entering force_install_dir before logging into Steam via login command.

force_install_dir c:\my_garrysmod_server\

You can then install or update the Garry's Mod Dedicated Server by using the command:

app_update 4020

It will slowly download or update.

If you wish to verify your server, enter this instead of the above:

app_update 4020 validate

Once it's done you can type quit at the console to exit or just close the SteamCMD window.

Automated

You probably don't want to do that every time you want to install/update a server. Don't worry - it supports command lines too.

steamcmd.exe +login anonymous +force_install_dir c:\my_garrysmod_server\ +app_update 4020 validate +quit

Running the server

After downloading and installing the server files you can now run the dedicated sever. You can either just run srcds.exe directly or use its command line interface like so:

srcds.exe +maxplayers 20 -console +gamemode sandbox +map gm_construct +sv_setsteamaccount <your token>

After initial installation

After installing your server you should set up your GSL Token and the server's location.

GSLT

Please see Steam Game Server Accounts (GSLT) for help with sv_setsteamaccount. This is mandatory. Your server's ranking will be penalized if you do not do this.

Server operator rules

Please make sure your server conforms to Server Operator Rules.

Location flag

Next you should set your server's location. This is done via the sv_location console variable. The convar should directly correspond to a flag icon stored in the materials/flags16/ folder, without the .png extension. The maximum length is currently set to 5 characters. The flag icon filenames follow the ISO 3166-1 alpha-2 country codes. (http://www.famfamfam.com/lab/icons/flags/)

For example sv_location gb will display the Great Britain flag, sv_location us will display the USA flag, etc. European Union has a special case: sv_location eu

Steam Workshop

Optionally you can add +host_workshop_collection <collectionID> to your command line to automatically install workshop addons onto your dedicated server. Please see Workshop for Dedicated Servers for help with workshop for dedicated servers.

Setting startup gamemode

The active gamemode is set via the gamemode ConVar. As a command line parameter it can be applied as such: +gamemode sandbox, where sandbox is the name of the gamemode folder as it appears in garrysmod/gamemodes/ or in the gamemodes/ folder of any addon, including workshop addons. If you do know know the folder name of a workshop addon, it is very likely this information is provided in the addons' description. If not, you can ask the addon author.

The active gamemode can be changed at any time with the gamemode convar and then changing the map (see below).

Setting the startup map.

Setting startup maps works identically to setting startup gamemode, but using the map concommand. As a command line parameter it would look like so: +map gm_construct, where gm_construct is name of the map file without the .bsp extension, inside the garrysmod/maps/ folder, or inside the maps/ folder of any addon. Same rule applies to workshop addons - check the addons workshop page description for map file name.

To gracefully change the active map to a different map (or to simply reload the map), you can use the changelevel command, like so: changelevel gm_flatgrass.

Peer to Peer

Dedicated server can function in peer-to-peer mode. It can be turned on via the -p2p command line parameter. On startup the server will tell you how players can connect to such a server manually.

Linux

Main article: Linux Dedicated Server Hosting

Installation

Install SteamCMD as per the recommendations from the Valve Developer Wiki.

Then install the GMod dedicated server in a similar manner to Windows:

steamcmd +login anonymous +force_install_dir ../gmodds +app_update 4020 validate +quit

The server is now available in ~/gmodds/.

cd ~/gmodds/ ./srcds_run -game garrysmod +maxplayers 32 +map gm_construct

Troubleshooting

If you get the error message

./steamcmd.sh: line 29: /home/$USER/Steam/linux32/steamcmd: No such file or directory

You are most likely running 64 a bit system and missing 32 bit libraries.

If the output of this command is x86_64, you are running a 64 bit system and need 32 bit libraries.

uname -m

See this article on the valve wiki.
32-bit libraries on 64-bit Linux systems

macOS

macOS dedicated servers are no longer shipped.

The Experimental Branches

To update your server to the development branch, you'll have to launch your SteamCMD and enter these commands manually:

For the pre-release branch:

For the x64 branch:

To revert back to stable branch:

The development branch is updated regularly.