CliArgumentAttribute Class

public class CliArgumentAttribute : Attribute

//Delegate-based model
//In Program.cs, add this simple code:
Cli.Run(([CliArgument] string argument1, bool option1) =>
{
    Console.WriteLine($@"Value for {nameof(argument1)} parameter is '{argument1}'");
    Console.WriteLine($@"Value for {nameof(option1)} parameter is '{option1}'");
});

//Or:
Cli.Run(Method);

void Method([CliArgument] string argument2, bool option2)
{
    Console.WriteLine($@"Value for {nameof(argument2)} parameter is '{argument2}'");
    Console.WriteLine($@"Value for {nameof(option2)} parameter is '{option2}'");
}

// Class-based model
// Create a simple class like this:

[CliCommand(Description = "A root cli command")]
public class RootCliCommand
{
    [CliOption(Description = "Description for Option1")]
    public string Option1 { get; set; } = "DefaultForOption1";

    [CliArgument(Description = "Description for Argument1")]
    public string Argument1 { get; set; }

    public void Run()
    {
        Console.WriteLine($@"Handler for '{GetType().FullName}' is run:");
        Console.WriteLine($@"Value for {nameof(Option1)} property is '{Option1}'");
        Console.WriteLine($@"Value for {nameof(Argument1)} property is '{Argument1}'");
        Console.WriteLine();
    }
}

        //In Program.cs, add this single line:
        Cli.Run<RootCliCommand>(args);

        //If you need to simply parse the command-line arguments without invocation, use this:
        var parseResult = Cli.Parse<RootCliCommand>(args);
        var rootCliCommand = parseResult.Bind<RootCliCommand>();

// Sub-commands can get a reference to the parent command by adding a property of the parent command type.

[CliCommand(Description = "A root cli command with children that can access parent commands")]
public class ParentCommandAccessorCliCommand
{
    [CliOption(
        Description = "This is a global option (Recursive option on the root command), it can appear anywhere on the command line",
        Recursive = true)]
    public string GlobalOption1 { get; set; } = "DefaultForGlobalOption1";

    [CliArgument(Description = "Description for RootArgument1")]
    public string RootArgument1 { get; set; }

    public void Run(CliContext context)
    {
        context.ShowValues();
    }

    [CliCommand(Description = "A nested level 1 sub-command which accesses the root command")]
    public class Level1SubCliCommand
    {
        [CliOption(
            Description = "This is global for all sub commands (it can appear anywhere after the level-1 verb)",
            Recursive = true)]
        public string Level1RecursiveOption1 { get; set; } = "DefaultForLevel1RecusiveOption1";

        [CliArgument(Description = "Description for Argument1")]
        public string Argument1 { get; set; }

        // The parent command gets automatically injected
        public ParentCommandAccessorCliCommand RootCommand { get; set; }

        public void Run(CliContext context)
        {
            context.ShowValues();
        }

        [CliCommand(Description = "A nested level 2 sub-command which accesses its parent commands")]
        public class Level2SubCliCommand
        {
            [CliOption(Description = "Description for Option1")]
            public string Option1 { get; set; } = "DefaultForOption1";

            [CliArgument(Description = "Description for Argument1")]
            public string Argument1 { get; set; }

            // All ancestor commands gets injected
            public ParentCommandAccessorCliCommand RootCommand { get; set; }
            public Level1SubCliCommand ParentCommand { get; set; }

            public void Run(CliContext context)
            {
                context.ShowValues();

                Console.WriteLine();
                Console.WriteLine(@$"Level1RecursiveOption1 = {ParentCommand.Level1RecursiveOption1}");
                Console.WriteLine(@$"parent Argument1 = {ParentCommand.Argument1}");
                Console.WriteLine(@$"GlobalOption1 = {RootCommand.GlobalOption1}");
                Console.WriteLine(@$"RootArgument1 = {RootCommand.RootArgument1}");
            }
        }
    }
}