diff --git a/src/argument_parser.ads b/src/argument_parser.ads
new file mode 100644
index 0000000..0dd250b
--- /dev/null
+++ b/src/argument_parser.ads
@@ -0,0 +1,36 @@
+package Argument_Parser is
+
+   type Option is interface;
+
+   function Parse (I : string) return Option is abstract;
+
+   type Argument_Parser is tagged private;
+
+   procedure Add_Positional (
+      Parser : in out Argument_Parser;
+      Input_Type : Option'Class;
+      Key : string;
+      Collect_Further_Inputs : Boolean := False);
+
+   procedure Add_Boolean_Option (
+      Parser : in out Argument_Parser;
+      Short_String : string;
+      Long_String : string)
+
+   procedure Add_Count_Option (
+      Parser : in out Argument_Parser;
+      Short_String : string;
+      Long_String : string;
+      Start_Count : Count := 0);
+
+   procedure Add_Option (
+      Parser : in out Argument_Parser;
+      Input_Type : Option'Class;
+      Short_String : string;
+      Long_String : string);
+
+private
+
+   type Argument_Parser is tagged null record;
+
+end Argument_Parser;