diff --git a/src/xtd.core/CMakeLists.txt b/src/xtd.core/CMakeLists.txt
index eefabb5e680d..528a6f321ec1 100644
--- a/src/xtd.core/CMakeLists.txt
+++ b/src/xtd.core/CMakeLists.txt
@@ -300,6 +300,8 @@ add_sources(
   include/xtd/sbyte
   include/xtd/sbyte_object.h
   include/xtd/sbyte_object
+  include/xtd/self.h
+  include/xtd/self
   include/xtd/semaphore.h
   include/xtd/semaphore
   include/xtd/signal.h
diff --git a/src/xtd.core/include/xtd/keywords.h b/src/xtd.core/include/xtd/keywords.h
index 31fdf1e156c2..5f3637e6fcc7 100644
--- a/src/xtd.core/include/xtd/keywords.h
+++ b/src/xtd.core/include/xtd/keywords.h
@@ -6,6 +6,7 @@
 #include "block_scope.h"
 #include "interface.h"
 #include "nameof.h"
+#include "self.h"
 #include "startup.h"
 #include "typeof.h"
 #include "unused.h"
diff --git a/src/xtd.core/include/xtd/self b/src/xtd.core/include/xtd/self
new file mode 100644
index 000000000000..155510788ee5
--- /dev/null
+++ b/src/xtd.core/include/xtd/self
@@ -0,0 +1,2 @@
+#pragma once
+#include "self.h"
diff --git a/src/xtd.core/include/xtd/self.h b/src/xtd.core/include/xtd/self.h
new file mode 100644
index 000000000000..6bfa48d98813
--- /dev/null
+++ b/src/xtd.core/include/xtd/self.h
@@ -0,0 +1,18 @@
+/// @file
+/// @brief Contains #self_ keyword.
+/// @copyright Copyright (c) 2023 Gammasoft. All rights reserved.
+#pragma once
+
+/// @brief The xtd namespace contains all fundamental classes to access Hardware, Os, System, and more.
+namespace xtd {
+}
+
+/// @brief The #self_ expression is a reference value expression whose value is the reference of the implicit object parameter (the object on which the non-static member function (up to C++23) implicit object member function (since C++23) is called).
+/// @par Namespace
+/// xtd
+/// @par Library
+/// xtd.core
+/// @ingroup xtd_core keywords
+/// @remarks #selt_ is equivalent to *this.
+#define self_\
+  (*this)
diff --git a/src/xtd.core/include/xtd/types.h b/src/xtd.core/include/xtd/types.h
index b7f99ae6cf35..6483df195f60 100644
--- a/src/xtd.core/include/xtd/types.h
+++ b/src/xtd.core/include/xtd/types.h
@@ -3,6 +3,7 @@
 /// @copyright Copyright (c) 2023 Gammasoft. All rights reserved.
 #pragma once
 #include "core_export.h"
+#include "self.h"
 /// @cond
 #define __XTD_VALUE_TYPE_NATIVE__
 #include <xtd/native/value_types>
diff --git a/src/xtd.core/include/xtd/xtd.core.h b/src/xtd.core/include/xtd/xtd.core.h
index aeea03d5e7e1..0de4b9bad062 100644
--- a/src/xtd.core/include/xtd/xtd.core.h
+++ b/src/xtd.core/include/xtd/xtd.core.h
@@ -332,6 +332,7 @@
 #include "reset_color.h"
 #include "sbyte.h"
 #include "sbyte_object.h"
+#include "self.h"
 #include "signal.h"
 #include "signal_cancel_event_args.h"
 #include "signal_cancel_event_handler.h"