diff --git a/src/MyFirstUDRKit.cpp b/src/MyFirstUDRKit.cpp
new file mode 100644
index 0000000..be23ae5
--- /dev/null
+++ b/src/MyFirstUDRKit.cpp
@@ -0,0 +1,95 @@
+/*
+ *  The contents of this file are subject to the Initial
+ *  Developer's Public License Version 1.0 (the "License");
+ *  you may not use this file except in compliance with the
+ *  License. You may obtain a copy of the License at
+ *  http://www.ibphoenix.com/main.nfs?a=ibphoenix&page=ibp_idpl.
+ *
+ *  Software distributed under the License is distributed AS IS,
+ *  WITHOUT WARRANTY OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing rights
+ *  and limitations under the License.
+ *
+ *  The Original Code was created by Adriano dos Santos Fernandes
+ *  for the Firebird Open Source RDBMS project.
+ *
+ *  Copyright (c) 2008 Adriano dos Santos Fernandes <adrianosf@gmail.com>
+ *  and all contributors signed below.
+ *
+ *  All Rights Reserved.
+ *  Contributor(s): ______________________________________.
+ *
+ *	Paul Reeves, 2023
+ *
+ */
+
+
+#define FB_UDR_STATUS_TYPE ::Firebird::ThrowStatusWrapper
+
+
+#include <ibase.h>
+#include <firebird/UdrCppEngine.h>
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifdef HAVE_MATH_H
+#include <math.h>
+#endif
+
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+
+#ifdef TIME_WITH_SYS_TIME
+# include <sys/time.h>
+# include <time.h>
+#else
+# ifdef HAVE_SYS_TIME_H
+#  include <sys/time.h>
+# else
+#  include <time.h>
+# endif
+#endif
+
+#ifdef HAVE_SYS_TIMEB_H
+# include <sys/timeb.h>
+#endif
+
+#ifdef HAVE_LOCALE_H
+#include <locale.h>
+#endif
+
+#include <limits>
+
+using namespace Firebird;
+
+/*** DDL
+create function flagged (
+    n1 integer,
+    n2 integer
+) returns integer
+    external name 'my_first_udr_kit!MFK_flagged'
+    engine udr;
+***/
+FB_UDR_BEGIN_FUNCTION(MFK_flagged)
+	FB_UDR_MESSAGE(InMessage,
+		(FB_INTEGER, flags)
+		(FB_INTEGER, flag)
+	);
+
+	FB_UDR_MESSAGE(OutMessage,
+		(FB_INTEGER, result)
+	);
+
+	FB_UDR_EXECUTE_FUNCTION
+	{
+  if ( flags == NULL ) {
+    return 0;
+  }
+  ISC_UINT64 i = ( 1ULL << *flag );
+  return ( *flags & i ) ? 1 : 0;
+	}
+FB_UDR_END_FUNCTION
+