[Plugin(1, "Extra Macro Component Plugin", "Adds new macro components to the macro builder!")]
public class PluginCore : IStartPlugin
{
    /// <summary>
    /// Should be used to check compatability with the
    /// current version of the bot.
    /// </summary>
    public override void OnLoad(int version, int subversion, int buildversion) { }
    public override PluginResponse OnEnable(IBotSettings botSettings) {
        /* Regular plugin content */
        return base.OnEnable(botSettings);
    }
}
    
public class TestMacroComponent : IExternalMacroComponent {
    
    public TestMacroComponent() {
        this.Category = MacroComponentCategory.Misc;
        this.Outputs = new IMacroOutputCollection(
            new KeyValuePair<string, ExternalMacroOutput>("success", new ExternalMacroOutput("Success", "This output gets called once the call finishes", true)),
            new KeyValuePair<string, ExternalMacroOutput>("output_internal_name", new ExternalMacroOutput("Error", "This output will never get called", false))
        );
        this.Variables = new IMacroVariableCollection(
            new KeyValuePair<string, ExternalMacroVariable>("variable_internal_name1", new ExternalMacroVariable(typeof(string), "Message", "What message should we send to chat?", "my default message!"))
        );
    }
    
    public override string GetName() {
        return "Test macro component";
    }
    
    public override string GetInternalName() {
        return "ex:test_macro_component";
    }
    
    public override string GetDescription() {
        return "This is a test macro component";
    }
    public override string GetInteractiveDescription() {
        var variableValue = GetVariable<string>("variable_internal_name1");
        return 
            string.IsNullOrWhiteSpace(variableValue) ? GetDescription() 
            : $"I will say {variableValue}.";
    }
    
    public override string Execute(IBotContext Context) {
        Context.Functions.Chat("My message: " + GetVariable<string>("variable_internal_name1"));
        return "success"; // or return "output_internal_name"
    }
}

public TestMacroComponent() {
    ...
    this.Outputs = new IMacroOutputCollection(
        new KeyValuePair<string, ExternalMacroOutput>("success", new ExternalMacroOutput("Success", "This output gets called once the call finishes", true)),
        new KeyValuePair<string, ExternalMacroOutput>("output_internal_name", new ExternalMacroOutput("Error", "This output will never get called", false))
    );
    ...
}