diff --git a/Program.cs b/Program.cs
index 9a2e2d2..2ad603a 100644
--- a/Program.cs
+++ b/Program.cs
@@ -1,5 +1,7 @@
 using System;
 using System.Xml;
+using System.Xml.Linq;
+using CommandLine;
 using Sprache;
 using XNeedle.Parser;
 using XNeedle.Parser.Elements;
@@ -9,24 +11,39 @@ namespace XNeedle
 {
     class Program
     {
-        static void Main()
+        public class Options
         {
-            var input = "$(\"//Device/Type[@ProductCode='#x0B583052' and @RevisionNo='#x00110000']\")";
+            [Value(0, MetaName = "xn", Required = true, HelpText = "XN transformation definition")]
+            public string XnDefinition { get; set; }
 
-            var rule = (Rule)XnParser.RuleObject.Parse(input);
+            [Option('i', "input", HelpText = "Input XML file", Required = true)]
+            public string Input { get; set; }
 
-            XmlDocument doc = new XmlDocument();  
-            doc.Load("ELx9xx.xml");
+            [Option('o', "output", HelpText = "Output XML file", Required = true)]
+            public string Output { get; set; }
 
-            rule.Transform(doc);
-
-            XmlWriterSettings settings = new XmlWriterSettings();
-            settings.Indent = true;
-            XmlWriter writer = XmlWriter.Create("El9xxFi.xml", settings);
-
-            doc.WriteContentTo(writer);
-
-            Console.WriteLine("Done.");
+            [Option('v', "verbose", Required = false, HelpText = "Set output to verbose messages.")]
+            public bool Verbose { get; set; }
         }
+        static void Main(string[] args)
+        {
+              CommandLine.Parser.Default.ParseArguments<Options>(args)
+                .WithParsed(RunOptions)
+                .WithNotParsed(HandleParseError);
+        }
+
+        static void RunOptions(Options opts)
+        {
+            var masterRule = (Rule)XnParser.RuleObject.Parse(File.ReadAllText(opts.XnDefinition));
+            var doc = new XmlDocument();
+            doc.PreserveWhitespace = true;
+            doc.Load(opts.Input);
+            masterRule.Transform(doc);
+            doc.Save(opts.Output);
+            
+            Console.WriteLine($"Applied \"{opts.XnDefinition}\" to \"{opts.Input}\" and saved result to \"{opts.Output}\"");
+        }
+
+        static void HandleParseError(IEnumerable<Error> errs) {}
     }
 }
\ No newline at end of file
diff --git a/XNeedle.csproj b/XNeedle.csproj
index 2054cd1..9dce10b 100644
--- a/XNeedle.csproj
+++ b/XNeedle.csproj
@@ -8,6 +8,7 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="CommandLineParser" Version="2.9.1" />
     <PackageReference Include="Sprache" Version="3.0.0-develop-00049" />
     <PackageReference Include="System.IO.Hashing" Version="10.0.0" />
   </ItemGroup>