Launch Options

Set launch options

Example

var launchOption = new MLaunchOption 
{
    Session = MSession.CreateOfflineSession("gamer123"),
    Features = new string[] { "feature_name" },

    JavaPath = "javaw.exe",
    MaximumRamMb = 4096,
    MinimumRamMb = 1024,
    DockName = "Minecraft",
    DockIcon = "/path/icon.icns",

    IsDemo = false,
    ScreenWidth = 1600,
    ScreenHeight = 900,
    FullScreen = false,
    QuickPlayPath = "/path/quickplay",
    QuickPlaySingleplayer = "world name",
    QuickPlayRealms = "realm id",
    ServerIp = "mc.hypixel.net",
    ServerPort = 25565,

    ClientId = "clientid",
    VersionType = "CmlLib",
    GameLauncherName = "CmlLib",
    GameLauncherVersion = "2",
    UserProperties = "{}",
    
    ArgumentDictionary = new Dictionary<string, string>
    {
        { "key", "value" },
        { "auth_xuid", "12345678" }
    },
    JvmArgumentOverrides = new MArgument[]
    {
        new MArgument("--key=value")
    },
    ExtraJvmArguments = new MArgument[]
    {
        new MArgument("--key=value"),
        MArgument.FromCommandLine("-Dminecraft.api.env=custom -Dminecraft.api.auth.host=https://invalid.invalid -Dminecraft.api.account.host=https://invalid.invalid -Dminecraft.api.session.host=https://invalid.invalid -Dminecraft.api.services.host=https://invalid.invalid"),
    },
    ExtraGameArguments = new MArgument[]
    {
        new MArgument("--key=value"),
        new MArgument(["--key1", "--key2", "value2"]),
    }
};

Session

Type: MSession

See Login and Sessions for how to log in Minecraft and get game session.

Game session (Username, UUID, AccessToken, etc...). If the value is null, the default session is used. (username tester123)

Features

Type: IEnumerable<string>

Enable features.

JavaPath

Type: string

Java binary path. If the value is null, ArgumentNullException is thrown.

MaximumRamMb

Type: int

-Xmx JVM parameter. It is used to set the maximum heap size of Minecraft. If the value is a negative value, ArgumentOutOfRangeException is thrown. The default value is 2048 (2GB) for X64, 1024 (1GB) for other platforms. Note: You can't set this property to any number higher than 1024 when using 32bit Java.

MinimumRamMb

Type: int

-Xms JVM parameter. It is used to set the minimum heap size of Minecraft. If the value is a negative value or greater than MaximumRamMb, ArgumentOutOfRangeException is thrown.

DockName

Type: string

macOS dock name of Minecraft. In some macOS versions, you must set this option. Known Issues

DockIcon

Type: string

macOS dock icon of minecraft. It should be an absolute file path to an image that has the dimensions 256x256 and is of the icns format.

IsDemo

Type: bool

Enable is_demo_user feature and launch a game in demo version.

ScreenWidth / ScreenHeight

Type: int

Initial window size of Minecraft. It works if the value of the two options is greater than 0. If the value of both options is 0, let the game decide the window size. If one of these options is negative, ArgumentOutOfRangeException will be thrown. Not all versions of Minecraft support this option.

FullScreen

Type: bool

Launch Minecraft as full screen. Not all versions of Minecraft support this option.

QuickPlayPath

Type: string

Set QuickPlayPath argument. QuickPlay

QuickPlaySingleplayer

Type: string

Set QuickPlaySingleplayer argument. QuickPlay

QuickPlayRealms

Type: string

Set QuickPlayRealms argument. QuickPlay

ServerIp / ServerPort

Type: string / int

Connecting to a server directly when Minecraft is loading is done. The default value of ServerPort is 25565. If ServerPort is not a valid port number (0-65535), ArgumentOutOfRangeException is thrown. If the starting version supports QuickPlay, the launcher will enable QuickPlayMultiplayer feature, otherwise the launcher will append --serverIp and --serverPort arguments.

note1: Not all versions of Minecraft support this option.

note2: The game would not be able to resolve the address if you pass a domain with an SRV record.

ClientId

Type: string

${clientid}

VersionType

Type: string

${version_type}. If the value is null, the Type property of the starting version is used. VersionType is displayed in the lower left corner of the main screen. Not all versions of Minecraft support this.

GameLauncherName

Type: string

${launcher_name}. The default value is minecraft-launcher , which is the same as the Mojang launcher.

GameLauncherVersion

Type: string

${launcher_version}. The default value is 2, which is the same as the Mojang launcher.

UserProperties

Type: string

${user_properties}. for Twitch livestreaming

ArgumentDictionary

Type: IReadOnlyDictionary<string, string>

When building an argument in the launcher, ${variable_name} will be replaced with the appropriate value. This option specifies variable_name as the key and the string to be replaced as the value.

JVMArgumentOverrides

Type: IEnumerable<MArgument>

Override all JVM arguments. When this option is not null, ExtraJVMArguments and JVMArguments are ignored.

ExtraJVMArguments

Type: IEnumerable<MArgument>

Set extra JVM arguments. Default arguments are:

-XX:+UnlockExperimentalVMOptions
-XX:+UseG1GC
-XX:G1NewSizePercent=20
-XX:G1ReservePercent=20
-XX:MaxGCPauseMillis=50
-XX:G1HeapRegionSize=16M

ExtraGameArguments

Type: IEnumerable<MArgument>

Set extra game arguments.