Dedicated server
Every launch argument, taken from ARGUMENTS.txt inside the official
server package for 1.2.1.5. No hosting company wrote this page, and nothing here is trying
to sell you a server.
Get the server
The dedicated server is a free download and needs no account:
The step most guides leave out
+app_license_request 1963720 must come before app_update.
Without it SteamCMD fails with Missing configuration — or
missing license for depot (No subscription) if you try download_depot —
even though the app is flagged free to download. With it, the download succeeds first time.
Command builder
Game ID validator
A Game ID must be 15–28 alphanumeric characters and may not contain
Y, y, x, 0 or O.
That rule is stated in the developer's own reference, and it is the reason a hand-typed ID is
rejected more often than people expect.
All launch arguments
| Flag | Setting | Values | Example |
|---|---|---|---|
-worldname | World Name | — | -worldname "Core Keeper Server" |
-worldseed | World Seed | — | -worldseed "Nice World" |
-hashedworldseed | Hashed World Seed | — | -hashedworldseed 42 |
-worldmode | World Mode | Normal, Hard, Creative, Casual | -worldmode Hard |
-season | Season | None, Easter, Halloween, Christmas, Valentine, Anniversary, CherryBlossom, LunarNewYear | -season Easter |
-activatecontent | Activate Content Bundles | AbioticFactor, BiomeStatues, GiantCicadaBossDungeon, GuaranteedOases, NatureBiomeCicadas | -activatecontent GiantCicadaBossDungeon |
-activateallcontent | Activate All Content Bundles | — | -activateallcontent |
-datapath | Data Path | — | -datapath "C:/Users/MyUser/Desktop/CKServerSaves" |
-gameid | Game ID | — | -gameid WH3rhzuk5TfbA4jFuZPg7SmbCHES |
-password | Password | — | -password "PleaseChangeMe" |
-port | Port | — | -port 7778 |
-ip | IP | — | -ip 0.0.0.0 |
-maxplayers | Max Players | — | -maxplayers 16 |
-allowonlyplatform | Platform | Steam, Epic, Microsoft, GOG | -allowonlyplatform Steam |
Content bundles
Activating a bundle is permanent for that world — the developer's reference
says there is no way to undo it. Available: AbioticFactor, BiomeStatues, GiantCicadaBossDungeon, GuaranteedOases, NatureBiomeCicadas.
Every argument in detail
World Name -worldname
Select the world name to use. This is the name that connecting clients will see in their network settings. If NAME contains spaces it must be place in quotation mark.
World Seed -worldseed
Select the world seed to use. This is the seed that is used to determine most random behavior in the game, most notably world generation and dungeon placement. SEED is an arbitrary string. If SEED contains spaces it must be placed in quotation marks. The seed behaves the same as if it was set during world creation in the regular game client. Only takes effect if set when the world is first created. Omit to generate a random seed.
Hashed World Seed -hashedworldseed
Similar to -worldseed, but specifies an already hashed seed. This is useful if you have lost access to the original seed string and only have the hashed version. Must be an unsigned 32-bit integer in the range 0 to 4294967295 (inclusive). Ignored if-worldseed is set.
World Mode -worldmode
Select the world mode to use. Corresponds to the same setting when creating a world using the regular game client. Default is Normal. Changing between creative and non-creative modes after the world has been created is not supported. Possible values are:
Values: Normal, Hard, Creative, Casual
Season -season
Set the server season. If omitted, the season is set based on the current system date. Possible values are:
Values: None, Easter, Halloween, Christmas, Valentine, Anniversary, CherryBlossom, LunarNewYear
Activate Content Bundles -activatecontent
Activate new content bundles if not already active for this game world. Once activated, the content bundle will stay active permanently for this world. There is no way to undo this. Multiple bundles may be activated at the same time by listing them separated by commas. Possible values are:
Values: AbioticFactor, BiomeStatues, GiantCicadaBossDungeon, GuaranteedOases, NatureBiomeCicadas
Activate All Content Bundles -activateallcontent
Automatically activates all available content bundles that are not already active for this game world.
Data Path -datapath
Set the save file location. If omitted, the server will default to a subfolder named "DedicatedServer" at the default Core Keeper save location.
Game ID -gameid
Select the game ID clients use to connect to this server. Game ID Needs to be at least 15 but at max 28 alphanumeric characters, and may not include Y,y,x,0, or O. If omitted or invalid, a random game ID will be generated.
Password -password
Select the password players should use when trying to join using direct connections with IP. Most characters are allowed if provided between "quotation marks", and maximum length password can be 28 characters. If omitted or invalid, a random password will be generated. The password is not used when connecting using game ID, because the game ID alone provides all capabilities a password would.
Port -port
Select a port to bind to. Setting the port will make the server accept direct connections, effectively enabling cross-play. The port must be open to accept incoming connections. Use -port 27015 to connect to a server on the same LAN. If omitted, the server will instead use the Steam relay network and won't accept direct connections using IP. This argument may only be set using command line arguments. Setting it in ServerConfig.json has no effect.
IP -ip
Sets the local IP address that the server binds to. Has no effect unless -port is also set. This argument may only be set using command line arguments. Setting it in ServerConfig.json has no effect. If not set, default value 0.0.0.0 is used, which will accept connections from any internal ip.Supports ipv6 addresses as well.
Max Players -maxplayers
Set the maximum number of players that can connect to the server. If omitted, the server will default to 8 players. Setting a higher player count may require more server resources or make the session unstable.
Platform -allowonlyplatform
Set the server only allow players from given platform. Effectively disables the cross-play from server. Has no effect unless -port is also set enabling Direct Connections. Possible values are:
Values: Steam, Epic, Microsoft, GOG