command

command contains the function for creating the minecraft command.

get_minecraft_command(version: str, minecraft_directory: Union[str, os.PathLike], options: MinecraftOptions) -> List[str]

Returns the command for running minecraft as list. The given command can be executed with subprocess. utils contains a function to get the default minecraft directory.

options is a dict:

options = {
    #This is needed
    "username": The Username,
    "uuid": uuid of the user,
    "token": the accessToken,
    #This is optional
    "executablePath": "java", # The path to the java executable
    "defaultExecutablePath": "java", # The path to the java executable if the version.json has none
    "jvmArguments": [], #The jvmArguments
    "launcherName": "minecraft-launcher-lib", # The name of your launcher
    "launcherVersion": "1.0", # The version of your launcher
    "gameDirectory": "/home/user/.minecraft", # The gameDirectory (default is the path given in arguments)
    "demo": False, # Run Minecraft in demo mode
    "customResolution": False, # Enable custom resolution
    "resolutionWidth": "854", # The resolution width
    "resolutionHeight": "480", # The resolution heigth
    "server": "example.com", # The ip of a server where Minecraft connect to after start
    "port": "123", # The port of a server where Minecraft connect to after start
    "nativesDirectory": "minecraft_directory/versions/version/natives", # The natives directory
    "enableLoggingConfig": False, # Enable use of the log4j configuration file
    "disableMultiplayer": False, # Disables the multiplayer
    "disableChat": False # Disables the chat
}

You can use the account module to get the needed information. For more information about the options take a look at the More Launch Options tutorial.