diff --git a/src/app/script/blend_mode.h b/src/app/script/blend_mode.h
new file mode 100644
index 000000000..0a2688f27
--- /dev/null
+++ b/src/app/script/blend_mode.h
@@ -0,0 +1,204 @@
+// Aseprite
+// Copyright (c) 2023  Igara Studio S.A.
+//
+// This program is distributed under the terms of
+// the End-User License Agreement for Aseprite.
+
+#ifndef APP_SCRIPT_BLEND_MODE_H_INCLUDED
+#define APP_SCRIPT_BLEND_MODE_H_INCLUDED
+#pragma once
+
+#include "base/convert_to.h"
+#include "doc/blend_mode.h"
+#include "os/paint.h"
+
+namespace app {
+namespace script {
+
+// Blend modes for doc::BlendMode and os::BlendMode, used in
+// Layer.blendMode and GraphicsContext.blendMode.
+enum class BlendMode : int {
+  CLEAR,
+  SRC,
+  DST,
+  SRC_OVER,
+  DST_OVER,
+  SRC_IN,
+  DST_IN,
+  SRC_OUT,
+  DST_OUT,
+  SRC_ATOP,
+  DST_ATOP,
+  XOR,
+  PLUS,
+  MODULATE,
+  MULTIPLY,
+  SCREEN,
+  OVERLAY,
+  DARKEN,
+  LIGHTEN,
+  COLOR_DODGE,
+  COLOR_BURN,
+  HARD_LIGHT,
+  SOFT_LIGHT,
+  DIFFERENCE,
+  EXCLUSION,
+  HUE,
+  SATURATION,
+  COLOR,
+  LUMINOSITY,
+  ADDITION,
+  SUBTRACT,
+  DIVIDE,
+};
+
+} // namespace script
+} // namespace app
+
+namespace base {
+
+template<>
+inline os::BlendMode convert_to(const app::script::BlendMode& from) {
+  switch (from) {
+    case app::script::BlendMode::CLEAR:       return os::BlendMode::Clear;
+    case app::script::BlendMode::SRC:         return os::BlendMode::Src;
+    case app::script::BlendMode::DST:         return os::BlendMode::Dst;
+    case app::script::BlendMode::SRC_OVER:    return os::BlendMode::SrcOver;
+    case app::script::BlendMode::DST_OVER:    return os::BlendMode::DstOver;
+    case app::script::BlendMode::SRC_IN:      return os::BlendMode::SrcIn;
+    case app::script::BlendMode::DST_IN:      return os::BlendMode::DstIn;
+    case app::script::BlendMode::SRC_OUT:     return os::BlendMode::SrcOut;
+    case app::script::BlendMode::DST_OUT:     return os::BlendMode::DstOut;
+    case app::script::BlendMode::SRC_ATOP:    return os::BlendMode::SrcATop;
+    case app::script::BlendMode::DST_ATOP:    return os::BlendMode::DstATop;
+    case app::script::BlendMode::XOR:         return os::BlendMode::Xor;
+    case app::script::BlendMode::PLUS:        return os::BlendMode::Plus;
+    case app::script::BlendMode::MODULATE:    return os::BlendMode::Modulate;
+    case app::script::BlendMode::MULTIPLY:    return os::BlendMode::Multiply;
+    case app::script::BlendMode::SCREEN:      return os::BlendMode::Screen;
+    case app::script::BlendMode::OVERLAY:     return os::BlendMode::Overlay;
+    case app::script::BlendMode::DARKEN:      return os::BlendMode::Darken;
+    case app::script::BlendMode::LIGHTEN:     return os::BlendMode::Lighten;
+    case app::script::BlendMode::COLOR_DODGE: return os::BlendMode::ColorDodge;
+    case app::script::BlendMode::COLOR_BURN:  return os::BlendMode::ColorBurn;
+    case app::script::BlendMode::HARD_LIGHT:  return os::BlendMode::HardLight;
+    case app::script::BlendMode::SOFT_LIGHT:  return os::BlendMode::SoftLight;
+    case app::script::BlendMode::DIFFERENCE:  return os::BlendMode::Difference;
+    case app::script::BlendMode::EXCLUSION:   return os::BlendMode::Exclusion;
+    case app::script::BlendMode::HUE:         return os::BlendMode::Hue;
+    case app::script::BlendMode::SATURATION:  return os::BlendMode::Saturation;
+    case app::script::BlendMode::COLOR:       return os::BlendMode::Color;
+    case app::script::BlendMode::LUMINOSITY:  return os::BlendMode::Luminosity;
+    case app::script::BlendMode::ADDITION:    return os::BlendMode::Plus;
+    // Default value
+    case app::script::BlendMode::SUBTRACT:
+    case app::script::BlendMode::DIVIDE:
+      return os::BlendMode::SrcOver;
+  }
+}
+
+template<>
+inline app::script::BlendMode convert_to(const os::BlendMode& from) {
+  switch (from) {
+    case os::BlendMode::Clear:       return app::script::BlendMode::CLEAR;
+    case os::BlendMode::Src:         return app::script::BlendMode::SRC;
+    case os::BlendMode::Dst:         return app::script::BlendMode::DST;
+    case os::BlendMode::SrcOver:     return app::script::BlendMode::SRC_OVER;
+    case os::BlendMode::DstOver:     return app::script::BlendMode::DST_OVER;
+    case os::BlendMode::SrcIn:       return app::script::BlendMode::SRC_IN;
+    case os::BlendMode::DstIn:       return app::script::BlendMode::DST_IN;
+    case os::BlendMode::SrcOut:      return app::script::BlendMode::SRC_OUT;
+    case os::BlendMode::DstOut:      return app::script::BlendMode::DST_OUT;
+    case os::BlendMode::SrcATop:     return app::script::BlendMode::SRC_ATOP;
+    case os::BlendMode::DstATop:     return app::script::BlendMode::DST_ATOP;
+    case os::BlendMode::Xor:         return app::script::BlendMode::XOR;
+    case os::BlendMode::Plus:        return app::script::BlendMode::PLUS;
+    case os::BlendMode::Modulate:    return app::script::BlendMode::MODULATE;
+    case os::BlendMode::Screen:      return app::script::BlendMode::SCREEN;
+    case os::BlendMode::Overlay:     return app::script::BlendMode::OVERLAY;
+    case os::BlendMode::Darken:      return app::script::BlendMode::DARKEN;
+    case os::BlendMode::Lighten:     return app::script::BlendMode::LIGHTEN;
+    case os::BlendMode::ColorDodge:  return app::script::BlendMode::COLOR_DODGE;
+    case os::BlendMode::ColorBurn:   return app::script::BlendMode::COLOR_BURN;
+    case os::BlendMode::HardLight:   return app::script::BlendMode::HARD_LIGHT;
+    case os::BlendMode::SoftLight:   return app::script::BlendMode::SOFT_LIGHT;
+    case os::BlendMode::Difference:  return app::script::BlendMode::DIFFERENCE;
+    case os::BlendMode::Exclusion:   return app::script::BlendMode::EXCLUSION;
+    case os::BlendMode::Multiply:    return app::script::BlendMode::MULTIPLY;
+    case os::BlendMode::Hue:         return app::script::BlendMode::HUE;
+    case os::BlendMode::Saturation:  return app::script::BlendMode::SATURATION;
+    case os::BlendMode::Color:       return app::script::BlendMode::COLOR;
+    case os::BlendMode::Luminosity:  return app::script::BlendMode::LUMINOSITY;
+  }
+}
+
+template<>
+inline doc::BlendMode convert_to(const app::script::BlendMode& from) {
+  switch (from) {
+    case app::script::BlendMode::SRC_OVER:    return doc::BlendMode::NORMAL;
+    case app::script::BlendMode::PLUS:        return doc::BlendMode::ADDITION;
+    case app::script::BlendMode::MULTIPLY:    return doc::BlendMode::MULTIPLY;
+    case app::script::BlendMode::SCREEN:      return doc::BlendMode::SCREEN;
+    case app::script::BlendMode::OVERLAY:     return doc::BlendMode::OVERLAY;
+    case app::script::BlendMode::DARKEN:      return doc::BlendMode::DARKEN;
+    case app::script::BlendMode::LIGHTEN:     return doc::BlendMode::LIGHTEN;
+    case app::script::BlendMode::COLOR_DODGE: return doc::BlendMode::COLOR_DODGE;
+    case app::script::BlendMode::COLOR_BURN:  return doc::BlendMode::COLOR_BURN;
+    case app::script::BlendMode::HARD_LIGHT:  return doc::BlendMode::HARD_LIGHT;
+    case app::script::BlendMode::SOFT_LIGHT:  return doc::BlendMode::SOFT_LIGHT;
+    case app::script::BlendMode::DIFFERENCE:  return doc::BlendMode::DIFFERENCE;
+    case app::script::BlendMode::EXCLUSION:   return doc::BlendMode::EXCLUSION;
+    case app::script::BlendMode::HUE:         return doc::BlendMode::HSL_HUE;
+    case app::script::BlendMode::SATURATION:  return doc::BlendMode::HSL_SATURATION;
+    case app::script::BlendMode::COLOR:       return doc::BlendMode::HSL_COLOR;
+    case app::script::BlendMode::LUMINOSITY:  return doc::BlendMode::HSL_LUMINOSITY;
+    case app::script::BlendMode::ADDITION:    return doc::BlendMode::ADDITION;
+    case app::script::BlendMode::SUBTRACT:    return doc::BlendMode::SUBTRACT;
+    case app::script::BlendMode::DIVIDE:      return doc::BlendMode::DIVIDE;
+    // Default value
+    case app::script::BlendMode::CLEAR:
+    case app::script::BlendMode::SRC:
+    case app::script::BlendMode::DST:
+    case app::script::BlendMode::DST_OVER:
+    case app::script::BlendMode::SRC_IN:
+    case app::script::BlendMode::DST_IN:
+    case app::script::BlendMode::SRC_OUT:
+    case app::script::BlendMode::DST_OUT:
+    case app::script::BlendMode::SRC_ATOP:
+    case app::script::BlendMode::DST_ATOP:
+    case app::script::BlendMode::XOR:
+    case app::script::BlendMode::MODULATE:
+      return doc::BlendMode::NORMAL;
+  }
+}
+
+template<>
+inline app::script::BlendMode convert_to(const doc::BlendMode& from) {
+  switch (from) {
+    case doc::BlendMode::NORMAL: return app::script::BlendMode::SRC_OVER;
+    case doc::BlendMode::MULTIPLY: return app::script::BlendMode::MULTIPLY;
+    case doc::BlendMode::SCREEN: return app::script::BlendMode::SCREEN;
+    case doc::BlendMode::OVERLAY: return app::script::BlendMode::OVERLAY;
+    case doc::BlendMode::DARKEN: return app::script::BlendMode::DARKEN;
+    case doc::BlendMode::LIGHTEN: return app::script::BlendMode::LIGHTEN;
+    case doc::BlendMode::COLOR_DODGE: return app::script::BlendMode::COLOR_DODGE;
+    case doc::BlendMode::COLOR_BURN: return app::script::BlendMode::COLOR_BURN;
+    case doc::BlendMode::HARD_LIGHT: return app::script::BlendMode::HARD_LIGHT;
+    case doc::BlendMode::SOFT_LIGHT: return app::script::BlendMode::SOFT_LIGHT;
+    case doc::BlendMode::DIFFERENCE: return app::script::BlendMode::DIFFERENCE;
+    case doc::BlendMode::EXCLUSION: return app::script::BlendMode::EXCLUSION;
+    case doc::BlendMode::HSL_HUE: return app::script::BlendMode::HUE;
+    case doc::BlendMode::HSL_SATURATION: return app::script::BlendMode::SATURATION;
+    case doc::BlendMode::HSL_COLOR: return app::script::BlendMode::COLOR;
+    case doc::BlendMode::HSL_LUMINOSITY: return app::script::BlendMode::LUMINOSITY;
+    case doc::BlendMode::ADDITION: return app::script::BlendMode::ADDITION;
+    case doc::BlendMode::SUBTRACT: return app::script::BlendMode::SUBTRACT;
+    case doc::BlendMode::DIVIDE: return app::script::BlendMode::DIVIDE;
+    default:
+      return app::script::BlendMode::SRC_OVER;
+  }
+}
+
+}
+
+#endif