diff --git a/core/input/input_event.cpp b/core/input/input_event.cpp
index 4ee09b0734..2d6c293c41 100644
--- a/core/input/input_event.cpp
+++ b/core/input/input_event.cpp
@@ -32,9 +32,11 @@
 
 #include "core/input/input_map.h"
 #include "core/input/shortcut.h"
+#include "core/math/transform_2d.h"
 #include "core/object/class_db.h"
 #include "core/os/keyboard.h"
 #include "core/os/os.h"
+#include "core/string/ustring.h"
 
 void InputEvent::set_device(int p_device) {
 	device = p_device;
diff --git a/core/input/input_event.h b/core/input/input_event.h
index 2a59d5815d..ec00dfdc58 100644
--- a/core/input/input_event.h
+++ b/core/input/input_event.h
@@ -32,9 +32,7 @@
 
 #include "core/input/input_enums.h"
 #include "core/io/resource.h"
-#include "core/math/transform_2d.h"
 #include "core/os/keyboard.h"
-#include "core/string/ustring.h"
 #include "core/typedefs.h"
 
 /**
@@ -43,6 +41,8 @@
  */
 
 class Shortcut;
+class String;
+struct Transform2D;
 
 /**
  * Input Modifier Status
diff --git a/core/io/resource.h b/core/io/resource.h
index 6528a87166..b83badf030 100644
--- a/core/io/resource.h
+++ b/core/io/resource.h
@@ -33,7 +33,6 @@
 #include "core/io/resource_uid.h"
 #include "core/object/gdvirtual.gen.h"
 #include "core/object/ref_counted.h"
-#include "core/templates/safe_refcount.h"
 #include "core/templates/self_list.h"
 
 class Node;
@@ -68,7 +67,6 @@ protected:
 	};
 
 private:
-	friend class ResBase;
 	friend class ResourceCache;
 
 	String name;
diff --git a/core/io/resource_uid.h b/core/io/resource_uid.h
index 3832d25d91..618f548b1e 100644
--- a/core/io/resource_uid.h
+++ b/core/io/resource_uid.h
@@ -30,8 +30,8 @@
 
 #pragma once
 
-#include "core/object/ref_counted.h"
-#include "core/string/string_name.h"
+#include "core/object/object.h"
+#include "core/string/ustring.h"
 #include "core/templates/hash_map.h"
 
 class FileAccess;
diff --git a/core/object/message_queue.h b/core/object/message_queue.h
index 460f02eccc..2722a1ed95 100644
--- a/core/object/message_queue.h
+++ b/core/object/message_queue.h
@@ -31,7 +31,7 @@
 #pragma once
 
 #include "core/object/object_id.h"
-#include "core/os/thread_safe.h"
+#include "core/os/mutex.h"
 #include "core/templates/local_vector.h"
 #include "core/templates/paged_allocator.h"
 #include "core/variant/variant.h"
diff --git a/core/os/keyboard.cpp b/core/os/keyboard.cpp
index c76744cde8..87bb29673b 100644
--- a/core/os/keyboard.cpp
+++ b/core/os/keyboard.cpp
@@ -31,6 +31,7 @@
 #include "keyboard.h"
 
 #include "core/os/os.h"
+#include "core/string/ustring.h"
 
 struct _KeyCodeText {
 	Key code;
diff --git a/core/os/keyboard.h b/core/os/keyboard.h
index 40f1c88665..8c64522abb 100644
--- a/core/os/keyboard.h
+++ b/core/os/keyboard.h
@@ -30,7 +30,9 @@
 
 #pragma once
 
-#include "core/string/ustring.h"
+class String;
+
+#include <cstdint>
 
 // Keep the values in this enum in sync with `_keycodes` in `keyboard.cpp`,
 // and the bindings in `core_constants.cpp`.
diff --git a/editor/animation/animation_library_editor.cpp b/editor/animation/animation_library_editor.cpp
index 0bf8ff02a6..35b61e35eb 100644
--- a/editor/animation/animation_library_editor.cpp
+++ b/editor/animation/animation_library_editor.cpp
@@ -46,6 +46,7 @@
 #include "scene/animation/animation_mixer.h"
 #include "scene/gui/line_edit.h"
 #include "scene/gui/margin_container.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/packed_scene.h"
 
 void AnimationLibraryEditor::set_animation_mixer(Object *p_mixer) {
diff --git a/editor/animation/animation_player_editor_plugin.cpp b/editor/animation/animation_player_editor_plugin.cpp
index ec656dedf7..5b33fae7e1 100644
--- a/editor/animation/animation_player_editor_plugin.cpp
+++ b/editor/animation/animation_player_editor_plugin.cpp
@@ -52,6 +52,7 @@
 #include "editor/themes/editor_theme_manager.h"
 #include "scene/animation/animation_tree.h"
 #include "scene/gui/separator.h"
+#include "scene/main/scene_tree.h"
 #include "scene/main/window.h"
 #include "scene/resources/animation.h"
 #include "scene/resources/image_texture.h"
@@ -471,12 +472,12 @@ void AnimationPlayerEditor::_animation_selected(int p_which) {
 			Node *root = player->get_node_or_null(player->get_root_node());
 
 			// Player shouldn't access parent if it's the scene root.
-			if (!root || (player == get_tree()->get_edited_scene_root() && player->get_root_node() == SceneStringName(path_pp))) {
+			if (!root || (player == get_tree()->get_edited_scene_root() && player->get_root_node() == NodePath(".."))) {
 				NodePath cached_root_path = player->get_path_to(get_cached_root_node());
 				if (player->get_node_or_null(cached_root_path) != nullptr) {
 					player->set_root_node(cached_root_path);
 				} else {
-					player->set_root_node(SceneStringName(path_pp)); // No other choice, preventing crash.
+					player->set_root_node(NodePath("..")); // No other choice, preventing crash.
 				}
 			} else {
 				cached_root_node_id = root->get_instance_id(); // Caching as `track_editor` can lose track of player's root node.
diff --git a/editor/animation/animation_track_editor.cpp b/editor/animation/animation_track_editor.cpp
index 84f87d4d5a..3ad6ad9319 100644
--- a/editor/animation/animation_track_editor.cpp
+++ b/editor/animation/animation_track_editor.cpp
@@ -64,6 +64,7 @@
 #include "scene/gui/spin_box.h"
 #include "scene/gui/texture_rect.h"
 #include "scene/gui/view_panner.h"
+#include "scene/main/scene_tree.h"
 #include "scene/main/window.h"
 #include "servers/audio/audio_stream.h"
 
diff --git a/editor/animation/animation_tree_editor_plugin.cpp b/editor/animation/animation_tree_editor_plugin.cpp
index c3b2f2ea15..e0b8e7975f 100644
--- a/editor/animation/animation_tree_editor_plugin.cpp
+++ b/editor/animation/animation_tree_editor_plugin.cpp
@@ -45,6 +45,7 @@
 #include "scene/gui/margin_container.h"
 #include "scene/gui/scroll_container.h"
 #include "scene/gui/separator.h"
+#include "scene/main/scene_tree.h"
 
 void AnimationTreeEditor::edit(AnimationTree *p_tree) {
 	if (p_tree && !p_tree->is_connected("animation_list_changed", callable_mp(this, &AnimationTreeEditor::_animation_list_changed))) {
diff --git a/editor/docks/scene_tree_dock.cpp b/editor/docks/scene_tree_dock.cpp
index a3cfde376b..1d1f1d5ce6 100644
--- a/editor/docks/scene_tree_dock.cpp
+++ b/editor/docks/scene_tree_dock.cpp
@@ -67,6 +67,7 @@
 #include "scene/audio/audio_stream_player.h"
 #include "scene/gui/box_container.h"
 #include "scene/gui/check_box.h"
+#include "scene/main/scene_tree.h"
 #include "scene/property_utils.h"
 #include "scene/resources/packed_scene.h"
 #include "servers/display/display_server.h"
diff --git a/editor/editor_log.cpp b/editor/editor_log.cpp
index 4b9aedc2c4..cadc772054 100644
--- a/editor/editor_log.cpp
+++ b/editor/editor_log.cpp
@@ -32,6 +32,7 @@
 
 #include "core/io/resource_loader.h"
 #include "core/object/callable_mp.h"
+#include "core/object/message_queue.h"
 #include "core/object/undo_redo.h"
 #include "core/os/keyboard.h"
 #include "core/os/os.h"
diff --git a/editor/export/editor_export_plugin.h b/editor/export/editor_export_plugin.h
index d9b2a9252f..69c13d6d41 100644
--- a/editor/export/editor_export_plugin.h
+++ b/editor/export/editor_export_plugin.h
@@ -31,6 +31,7 @@
 #pragma once
 
 #include "core/os/shared_object.h"
+#include "core/variant/typed_array.h"
 #include "editor_export_platform.h"
 #include "editor_export_preset.h"
 #include "scene/main/node.h"
diff --git a/editor/file_system/editor_file_system.cpp b/editor/file_system/editor_file_system.cpp
index 69fbfb5a3a..5df769aa70 100644
--- a/editor/file_system/editor_file_system.cpp
+++ b/editor/file_system/editor_file_system.cpp
@@ -47,6 +47,7 @@
 #include "editor/script/script_editor_plugin.h"
 #include "editor/settings/editor_settings.h"
 #include "editor/settings/project_settings_editor.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/packed_scene.h"
 #include "servers/display/display_server.h"
 
diff --git a/editor/gui/credits_roll.cpp b/editor/gui/credits_roll.cpp
index c2f9b681c5..ae279842b7 100644
--- a/editor/gui/credits_roll.cpp
+++ b/editor/gui/credits_roll.cpp
@@ -43,6 +43,7 @@
 #include "scene/gui/color_rect.h"
 #include "scene/gui/label.h"
 #include "scene/gui/texture_rect.h"
+#include "scene/main/scene_tree.h"
 #include "scene/main/window.h"
 
 Label *CreditsRoll::_create_label(const String &p_with_text, LabelSize p_size) {
diff --git a/editor/gui/editor_about.cpp b/editor/gui/editor_about.cpp
index f372ccf90a..db1e9d4350 100644
--- a/editor/gui/editor_about.cpp
+++ b/editor/gui/editor_about.cpp
@@ -50,6 +50,7 @@
 #include "scene/gui/tab_container.h"
 #include "scene/gui/texture_rect.h"
 #include "scene/gui/tree.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/style_box.h"
 
 void EditorAbout::_notification(int p_what) {
diff --git a/editor/gui/editor_toaster.cpp b/editor/gui/editor_toaster.cpp
index 68ff49350b..abff2708da 100644
--- a/editor/gui/editor_toaster.cpp
+++ b/editor/gui/editor_toaster.cpp
@@ -32,6 +32,7 @@
 
 #include "core/object/callable_mp.h"
 #include "core/object/class_db.h"
+#include "core/object/message_queue.h"
 #include "editor/editor_string_names.h"
 #include "editor/settings/editor_settings.h"
 #include "editor/themes/editor_scale.h"
diff --git a/editor/inspector/editor_inspector.cpp b/editor/inspector/editor_inspector.cpp
index 4d07334192..d0e9ba94a5 100644
--- a/editor/inspector/editor_inspector.cpp
+++ b/editor/inspector/editor_inspector.cpp
@@ -59,6 +59,7 @@
 #include "scene/gui/separator.h"
 #include "scene/gui/spin_box.h"
 #include "scene/gui/texture_rect.h"
+#include "scene/main/scene_tree.h"
 #include "scene/main/timer.h"
 #include "scene/property_utils.h"
 #include "scene/resources/packed_scene.h"
diff --git a/editor/inspector/editor_properties.cpp b/editor/inspector/editor_properties.cpp
index 1fca7e978c..c90f29de93 100644
--- a/editor/inspector/editor_properties.cpp
+++ b/editor/inspector/editor_properties.cpp
@@ -59,6 +59,7 @@
 #include "scene/gui/color_picker.h"
 #include "scene/gui/grid_container.h"
 #include "scene/gui/text_edit.h"
+#include "scene/main/scene_tree.h"
 #include "scene/main/window.h"
 #include "scene/resources/font.h"
 #include "scene/resources/mesh.h"
diff --git a/editor/inspector/editor_properties_array_dict.cpp b/editor/inspector/editor_properties_array_dict.cpp
index ad7c666392..4d3f66deab 100644
--- a/editor/inspector/editor_properties_array_dict.cpp
+++ b/editor/inspector/editor_properties_array_dict.cpp
@@ -46,6 +46,7 @@
 #include "editor/themes/editor_scale.h"
 #include "scene/gui/button.h"
 #include "scene/gui/margin_container.h"
+#include "scene/main/scene_tree.h"
 
 bool EditorPropertyArrayObject::_set(const StringName &p_name, const Variant &p_value) {
 	String name = p_name;
diff --git a/editor/inspector/editor_resource_preview.cpp b/editor/inspector/editor_resource_preview.cpp
index d3f5b41106..e61ce81b43 100644
--- a/editor/inspector/editor_resource_preview.cpp
+++ b/editor/inspector/editor_resource_preview.cpp
@@ -36,6 +36,7 @@
 #include "core/io/resource_saver.h"
 #include "core/object/callable_mp.h"
 #include "core/object/class_db.h"
+#include "core/os/main_loop.h"
 #include "core/os/os.h"
 #include "core/variant/variant_utility.h"
 #include "editor/editor_node.h"
@@ -43,6 +44,7 @@
 #include "editor/file_system/editor_paths.h"
 #include "editor/settings/editor_settings.h"
 #include "editor/themes/editor_scale.h"
+#include "scene/main/scene_tree.h"
 #include "scene/main/window.h"
 #include "scene/resources/image_texture.h"
 #include "servers/display/display_server.h"
diff --git a/editor/run/editor_run_bar.cpp b/editor/run/editor_run_bar.cpp
index e2967d4b2d..1b5f7e7373 100644
--- a/editor/run/editor_run_bar.cpp
+++ b/editor/run/editor_run_bar.cpp
@@ -50,6 +50,7 @@
 #include "scene/gui/button.h"
 #include "scene/gui/menu_button.h"
 #include "scene/gui/panel_container.h"
+#include "scene/main/scene_tree.h"
 
 #ifndef XR_DISABLED
 #include "servers/xr/xr_server.h"
diff --git a/editor/run/game_view_plugin.cpp b/editor/run/game_view_plugin.cpp
index f15d5bf703..97d816617b 100644
--- a/editor/run/game_view_plugin.cpp
+++ b/editor/run/game_view_plugin.cpp
@@ -56,6 +56,7 @@
 #include "scene/gui/menu_button.h"
 #include "scene/gui/panel.h"
 #include "scene/gui/separator.h"
+#include "scene/main/scene_tree.h"
 #include "servers/display/display_server.h"
 
 void GameViewDebugger::_session_started(Ref<EditorDebuggerSession> p_session) {
diff --git a/editor/scene/2d/abstract_polygon_2d_editor.cpp b/editor/scene/2d/abstract_polygon_2d_editor.cpp
index f4567876e0..3b6e79b584 100644
--- a/editor/scene/2d/abstract_polygon_2d_editor.cpp
+++ b/editor/scene/2d/abstract_polygon_2d_editor.cpp
@@ -41,6 +41,7 @@
 #include "editor/themes/editor_scale.h"
 #include "scene/gui/button.h"
 #include "scene/gui/dialogs.h"
+#include "scene/main/scene_tree.h"
 
 bool AbstractPolygon2DEditor::Vertex::operator==(const AbstractPolygon2DEditor::Vertex &p_vertex) const {
 	return polygon == p_vertex.polygon && vertex == p_vertex.vertex;
diff --git a/editor/scene/2d/physics/cast_2d_editor_plugin.cpp b/editor/scene/2d/physics/cast_2d_editor_plugin.cpp
index e9eab537db..729222e7b4 100644
--- a/editor/scene/2d/physics/cast_2d_editor_plugin.cpp
+++ b/editor/scene/2d/physics/cast_2d_editor_plugin.cpp
@@ -36,6 +36,7 @@
 #include "editor/scene/canvas_item_editor_plugin.h"
 #include "scene/2d/physics/ray_cast_2d.h"
 #include "scene/2d/physics/shape_cast_2d.h"
+#include "scene/main/scene_tree.h"
 #include "scene/main/viewport.h"
 
 void Cast2DEditor::_notification(int p_what) {
diff --git a/editor/scene/2d/physics/collision_shape_2d_editor_plugin.cpp b/editor/scene/2d/physics/collision_shape_2d_editor_plugin.cpp
index b05f621f3a..3383dc001a 100644
--- a/editor/scene/2d/physics/collision_shape_2d_editor_plugin.cpp
+++ b/editor/scene/2d/physics/collision_shape_2d_editor_plugin.cpp
@@ -37,6 +37,7 @@
 #include "editor/editor_undo_redo_manager.h"
 #include "editor/scene/canvas_item_editor_plugin.h"
 #include "editor/settings/editor_settings.h"
+#include "scene/main/scene_tree.h"
 #include "scene/main/viewport.h"
 #include "scene/resources/2d/capsule_shape_2d.h"
 #include "scene/resources/2d/circle_shape_2d.h"
diff --git a/editor/scene/2d/polygon_2d_editor_plugin.cpp b/editor/scene/2d/polygon_2d_editor_plugin.cpp
index 4650faf0d7..ad8dee0064 100644
--- a/editor/scene/2d/polygon_2d_editor_plugin.cpp
+++ b/editor/scene/2d/polygon_2d_editor_plugin.cpp
@@ -56,6 +56,7 @@
 #include "scene/gui/spin_box.h"
 #include "scene/gui/split_container.h"
 #include "scene/gui/view_panner.h"
+#include "scene/main/scene_tree.h"
 #include "servers/rendering/rendering_server.h"
 
 Node2D *Polygon2DEditor::_get_node() const {
diff --git a/editor/scene/2d/sprite_2d_editor_plugin.cpp b/editor/scene/2d/sprite_2d_editor_plugin.cpp
index 84af8cead6..e9b46ea427 100644
--- a/editor/scene/2d/sprite_2d_editor_plugin.cpp
+++ b/editor/scene/2d/sprite_2d_editor_plugin.cpp
@@ -48,6 +48,7 @@
 #include "scene/gui/menu_button.h"
 #include "scene/gui/panel.h"
 #include "scene/gui/view_panner.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/mesh.h"
 #include "thirdparty/clipper2/include/clipper2/clipper.h"
 
diff --git a/editor/scene/2d/tiles/tile_data_editors.cpp b/editor/scene/2d/tiles/tile_data_editors.cpp
index 7db36289da..fe0075731e 100644
--- a/editor/scene/2d/tiles/tile_data_editors.cpp
+++ b/editor/scene/2d/tiles/tile_data_editors.cpp
@@ -37,6 +37,7 @@
 #include "core/object/callable_mp.h"
 #include "core/object/class_db.h"
 #include "core/os/keyboard.h"
+#include "scene/main/scene_tree.h"
 
 #include "editor/editor_node.h"
 #include "editor/editor_string_names.h"
diff --git a/editor/scene/2d/tiles/tile_map_layer_editor.cpp b/editor/scene/2d/tiles/tile_map_layer_editor.cpp
index d9c5d0fb70..2843288b31 100644
--- a/editor/scene/2d/tiles/tile_map_layer_editor.cpp
+++ b/editor/scene/2d/tiles/tile_map_layer_editor.cpp
@@ -51,6 +51,7 @@
 #include "scene/2d/tile_map_layer.h"
 #include "scene/gui/grid_container.h"
 #include "scene/gui/split_container.h"
+#include "scene/main/scene_tree.h"
 
 void SwitchSeparator::set_vertical(bool p_vertical) {
 	h_separator->set_visible(p_vertical);
diff --git a/editor/scene/2d/tiles/tiles_editor_plugin.cpp b/editor/scene/2d/tiles/tiles_editor_plugin.cpp
index 9e57009197..18d2e04ed9 100644
--- a/editor/scene/2d/tiles/tiles_editor_plugin.cpp
+++ b/editor/scene/2d/tiles/tiles_editor_plugin.cpp
@@ -48,6 +48,7 @@
 #include "scene/2d/tile_map_layer.h"
 #include "scene/gui/button.h"
 #include "scene/gui/control.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/2d/tile_set.h"
 #include "scene/resources/image_texture.h"
 #include "servers/rendering/rendering_server.h"
diff --git a/editor/scene/3d/gpu_particles_collision_sdf_editor_plugin.cpp b/editor/scene/3d/gpu_particles_collision_sdf_editor_plugin.cpp
index 48903e6540..5b8a49ab8c 100644
--- a/editor/scene/3d/gpu_particles_collision_sdf_editor_plugin.cpp
+++ b/editor/scene/3d/gpu_particles_collision_sdf_editor_plugin.cpp
@@ -35,6 +35,7 @@
 #include "editor/editor_node.h"
 #include "editor/editor_string_names.h"
 #include "editor/gui/editor_file_dialog.h"
+#include "scene/main/scene_tree.h"
 
 void GPUParticlesCollisionSDF3DEditorPlugin::_bake() {
 	if (col_sdf) {
diff --git a/editor/scene/3d/lightmap_gi_editor_plugin.cpp b/editor/scene/3d/lightmap_gi_editor_plugin.cpp
index 27547779f7..373a31c50a 100644
--- a/editor/scene/3d/lightmap_gi_editor_plugin.cpp
+++ b/editor/scene/3d/lightmap_gi_editor_plugin.cpp
@@ -36,6 +36,7 @@
 #include "editor/editor_node.h"
 #include "editor/editor_string_names.h"
 #include "editor/gui/editor_file_dialog.h"
+#include "scene/main/scene_tree.h"
 #include "servers/display/display_server.h"
 #include "servers/rendering/rendering_server.h"
 
diff --git a/editor/scene/3d/mesh_instance_3d_editor_plugin.cpp b/editor/scene/3d/mesh_instance_3d_editor_plugin.cpp
index 18a53829c8..e49841fb3c 100644
--- a/editor/scene/3d/mesh_instance_3d_editor_plugin.cpp
+++ b/editor/scene/3d/mesh_instance_3d_editor_plugin.cpp
@@ -45,6 +45,7 @@
 #include "scene/gui/dialogs.h"
 #include "scene/gui/menu_button.h"
 #include "scene/gui/spin_box.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/3d/box_shape_3d.h"
 #include "scene/resources/3d/capsule_shape_3d.h"
 #include "scene/resources/3d/concave_polygon_shape_3d.h"
diff --git a/editor/scene/3d/node_3d_editor_gizmos.cpp b/editor/scene/3d/node_3d_editor_gizmos.cpp
index b7caf8a658..1dc497091d 100644
--- a/editor/scene/3d/node_3d_editor_gizmos.cpp
+++ b/editor/scene/3d/node_3d_editor_gizmos.cpp
@@ -37,6 +37,7 @@
 #include "editor/editor_string_names.h"
 #include "editor/scene/3d/node_3d_editor_plugin.h"
 #include "editor/settings/editor_settings.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/3d/primitive_meshes.h"
 #include "servers/rendering/rendering_server.h"
 
diff --git a/editor/scene/3d/node_3d_editor_plugin.cpp b/editor/scene/3d/node_3d_editor_plugin.cpp
index 7a397df852..0515c163ab 100644
--- a/editor/scene/3d/node_3d_editor_plugin.cpp
+++ b/editor/scene/3d/node_3d_editor_plugin.cpp
@@ -105,6 +105,7 @@
 #include "scene/gui/separator.h"
 #include "scene/gui/split_container.h"
 #include "scene/gui/subviewport_container.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/3d/sky_material.h"
 #include "scene/resources/packed_scene.h"
 #include "scene/resources/sky.h"
diff --git a/editor/scene/3d/occluder_instance_3d_editor_plugin.cpp b/editor/scene/3d/occluder_instance_3d_editor_plugin.cpp
index b8cb563fad..ce6c44c37a 100644
--- a/editor/scene/3d/occluder_instance_3d_editor_plugin.cpp
+++ b/editor/scene/3d/occluder_instance_3d_editor_plugin.cpp
@@ -35,6 +35,7 @@
 #include "editor/editor_node.h"
 #include "editor/editor_string_names.h"
 #include "editor/gui/editor_file_dialog.h"
+#include "scene/main/scene_tree.h"
 
 void OccluderInstance3DEditorPlugin::_bake_select_file(const String &p_file) {
 	if (occluder_instance) {
diff --git a/editor/scene/3d/polygon_3d_editor_plugin.cpp b/editor/scene/3d/polygon_3d_editor_plugin.cpp
index af11024f6c..a503e1bec6 100644
--- a/editor/scene/3d/polygon_3d_editor_plugin.cpp
+++ b/editor/scene/3d/polygon_3d_editor_plugin.cpp
@@ -42,6 +42,7 @@
 #include "editor/scene/canvas_item_editor_plugin.h"
 #include "editor/settings/editor_settings.h"
 #include "scene/3d/camera_3d.h"
+#include "scene/main/scene_tree.h"
 
 void Polygon3DEditor::_notification(int p_what) {
 	switch (p_what) {
diff --git a/editor/scene/3d/skeleton_3d_editor_plugin.cpp b/editor/scene/3d/skeleton_3d_editor_plugin.cpp
index 3f65eb86a7..a73e62fd2c 100644
--- a/editor/scene/3d/skeleton_3d_editor_plugin.cpp
+++ b/editor/scene/3d/skeleton_3d_editor_plugin.cpp
@@ -48,6 +48,7 @@
 #include "scene/3d/physics/physical_bone_simulator_3d.h"
 #include "scene/gui/separator.h"
 #include "scene/gui/texture_rect.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/3d/capsule_shape_3d.h"
 #include "scene/resources/skeleton_profile.h"
 #include "scene/resources/surface_tool.h"
diff --git a/editor/scene/3d/voxel_gi_editor_plugin.cpp b/editor/scene/3d/voxel_gi_editor_plugin.cpp
index e3eeda9bcf..7ef0187ab8 100644
--- a/editor/scene/3d/voxel_gi_editor_plugin.cpp
+++ b/editor/scene/3d/voxel_gi_editor_plugin.cpp
@@ -37,6 +37,7 @@
 #include "editor/editor_node.h"
 #include "editor/editor_string_names.h"
 #include "editor/gui/editor_file_dialog.h"
+#include "scene/main/scene_tree.h"
 
 void VoxelGIEditorPlugin::_bake() {
 	if (voxel_gi) {
diff --git a/editor/scene/canvas_item_editor_plugin.cpp b/editor/scene/canvas_item_editor_plugin.cpp
index ab1b925295..24c56032ad 100644
--- a/editor/scene/canvas_item_editor_plugin.cpp
+++ b/editor/scene/canvas_item_editor_plugin.cpp
@@ -68,6 +68,7 @@
 #include "scene/gui/subviewport_container.h"
 #include "scene/gui/view_panner.h"
 #include "scene/main/canvas_layer.h"
+#include "scene/main/scene_tree.h"
 #include "scene/main/timer.h"
 #include "scene/main/window.h"
 #include "scene/resources/packed_scene.h"
diff --git a/editor/scene/connections_dialog.cpp b/editor/scene/connections_dialog.cpp
index 137aaf362b..594f9f7930 100644
--- a/editor/scene/connections_dialog.cpp
+++ b/editor/scene/connections_dialog.cpp
@@ -56,6 +56,7 @@
 #include "scene/gui/margin_container.h"
 #include "scene/gui/popup_menu.h"
 #include "scene/gui/spin_box.h"
+#include "scene/main/scene_tree.h"
 #include "servers/display/display_server.h"
 
 static Node *_find_first_script(Node *p_root, Node *p_node) {
diff --git a/editor/scene/gui/theme_editor_preview.h b/editor/scene/gui/theme_editor_preview.h
index bddcfc4448..28f56d43c7 100644
--- a/editor/scene/gui/theme_editor_preview.h
+++ b/editor/scene/gui/theme_editor_preview.h
@@ -37,6 +37,7 @@ class Button;
 class ColorPickerButton;
 class ColorRect;
 class MarginContainer;
+class PackedScene;
 class ScrollContainer;
 
 class ThemeEditorPreview : public VBoxContainer {
diff --git a/editor/scene/packed_scene_editor_plugin.h b/editor/scene/packed_scene_editor_plugin.h
index 2463f19118..ba22cf75f9 100644
--- a/editor/scene/packed_scene_editor_plugin.h
+++ b/editor/scene/packed_scene_editor_plugin.h
@@ -34,6 +34,8 @@
 #include "editor/plugins/editor_plugin.h"
 #include "scene/gui/box_container.h"
 
+class PackedScene;
+
 class PackedSceneEditor : public VBoxContainer {
 	GDCLASS(PackedSceneEditor, VBoxContainer);
 
diff --git a/editor/scene/scene_tree_editor.cpp b/editor/scene/scene_tree_editor.cpp
index de9f145a34..7fe1bf079b 100644
--- a/editor/scene/scene_tree_editor.cpp
+++ b/editor/scene/scene_tree_editor.cpp
@@ -54,6 +54,7 @@
 #include "scene/gui/flow_container.h"
 #include "scene/gui/label.h"
 #include "scene/gui/texture_rect.h"
+#include "scene/main/scene_tree.h"
 #include "scene/main/window.h"
 #include "scene/resources/packed_scene.h"
 
diff --git a/editor/scene/sprite_frames_editor_plugin.cpp b/editor/scene/sprite_frames_editor_plugin.cpp
index 051165b90a..0ff33bdf58 100644
--- a/editor/scene/sprite_frames_editor_plugin.cpp
+++ b/editor/scene/sprite_frames_editor_plugin.cpp
@@ -56,6 +56,7 @@
 #include "scene/gui/panel_container.h"
 #include "scene/gui/separator.h"
 #include "scene/gui/split_container.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/atlas_texture.h"
 
 static void _draw_shadowed_line(Control *p_control, const Point2 &p_from, const Size2 &p_size, const Size2 &p_shadow_offset, Color p_color, Color p_shadow_color) {
diff --git a/editor/scene/texture/texture_region_editor_plugin.cpp b/editor/scene/texture/texture_region_editor_plugin.cpp
index 3ec4e2fab1..2672e7ffbb 100644
--- a/editor/scene/texture/texture_region_editor_plugin.cpp
+++ b/editor/scene/texture/texture_region_editor_plugin.cpp
@@ -47,6 +47,7 @@
 #include "scene/gui/separator.h"
 #include "scene/gui/spin_box.h"
 #include "scene/gui/view_panner.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/atlas_texture.h"
 #include "scene/resources/style_box_texture.h"
 #include "servers/rendering/rendering_server.h"
diff --git a/editor/script/find_in_files.cpp b/editor/script/find_in_files.cpp
index afe0f05039..ff340d0c3e 100644
--- a/editor/script/find_in_files.cpp
+++ b/editor/script/find_in_files.cpp
@@ -50,6 +50,7 @@
 #include "scene/gui/progress_bar.h"
 #include "scene/gui/tab_container.h"
 #include "scene/gui/tree.h"
+#include "scene/main/scene_tree.h"
 
 const char *FindInFiles::SIGNAL_RESULT_FOUND = "result_found";
 
diff --git a/editor/script/script_editor_plugin.cpp b/editor/script/script_editor_plugin.cpp
index e0899f5644..eb03a12d71 100644
--- a/editor/script/script_editor_plugin.cpp
+++ b/editor/script/script_editor_plugin.cpp
@@ -77,6 +77,7 @@
 #include "scene/gui/tab_container.h"
 #include "scene/gui/texture_rect.h"
 #include "scene/main/node.h"
+#include "scene/main/scene_tree.h"
 #include "scene/main/window.h"
 #include "servers/display/display_server.h"
 
diff --git a/editor/script/script_text_editor.cpp b/editor/script/script_text_editor.cpp
index 7756839a8f..277ca4c919 100644
--- a/editor/script/script_text_editor.cpp
+++ b/editor/script/script_text_editor.cpp
@@ -56,6 +56,7 @@
 #include "scene/gui/menu_button.h"
 #include "scene/gui/rich_text_label.h"
 #include "scene/gui/split_container.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/style_box_flat.h"
 #include "servers/rendering/rendering_server.h"
 
diff --git a/editor/settings/editor_autoload_settings.cpp b/editor/settings/editor_autoload_settings.cpp
index 3613125d55..863b3c0c72 100644
--- a/editor/settings/editor_autoload_settings.cpp
+++ b/editor/settings/editor_autoload_settings.cpp
@@ -43,6 +43,7 @@
 #include "editor/settings/project_settings_editor.h"
 #include "scene/gui/button.h"
 #include "scene/gui/tree.h"
+#include "scene/main/scene_tree.h"
 #include "scene/main/window.h"
 #include "scene/resources/packed_scene.h"
 
diff --git a/editor/shader/shader_create_dialog.cpp b/editor/shader/shader_create_dialog.cpp
index 6378b0b7b7..df031576e6 100644
--- a/editor/shader/shader_create_dialog.cpp
+++ b/editor/shader/shader_create_dialog.cpp
@@ -39,6 +39,7 @@
 #include "editor/gui/editor_validation_panel.h"
 #include "editor/shader/editor_shader_language_plugin.h"
 #include "editor/themes/editor_scale.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/shader_include.h"
 #include "servers/rendering/shader_types.h"
 
diff --git a/modules/csg/csg_shape.cpp b/modules/csg/csg_shape.cpp
index 720ee4e808..8119666f44 100644
--- a/modules/csg/csg_shape.cpp
+++ b/modules/csg/csg_shape.cpp
@@ -34,6 +34,7 @@
 #include "core/math/geometry_2d.h"
 #include "core/object/callable_mp.h"
 #include "core/object/class_db.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/3d/navigation_mesh_source_geometry_data_3d.h"
 #include "scene/resources/navigation_mesh.h"
 #include "servers/rendering/rendering_server.h"
diff --git a/modules/csg/editor/csg_gizmos.cpp b/modules/csg/editor/csg_gizmos.cpp
index 91e6e17ffc..0ff2417313 100644
--- a/modules/csg/editor/csg_gizmos.cpp
+++ b/modules/csg/editor/csg_gizmos.cpp
@@ -43,6 +43,7 @@
 #include "scene/3d/physics/collision_shape_3d.h"
 #include "scene/gui/dialogs.h"
 #include "scene/gui/menu_button.h"
+#include "scene/main/scene_tree.h"
 
 void CSGShapeEditor::_node_removed(Node *p_node) {
 	if (p_node == node) {
diff --git a/modules/gltf/editor/editor_scene_exporter_gltf_plugin.cpp b/modules/gltf/editor/editor_scene_exporter_gltf_plugin.cpp
index 904613ff1f..4d00b2b6b9 100644
--- a/modules/gltf/editor/editor_scene_exporter_gltf_plugin.cpp
+++ b/modules/gltf/editor/editor_scene_exporter_gltf_plugin.cpp
@@ -40,6 +40,7 @@
 #include "editor/inspector/editor_inspector.h"
 #include "editor/themes/editor_scale.h"
 #include "scene/gui/dialogs.h"
+#include "scene/main/scene_tree.h"
 
 String SceneExporterGLTFPlugin::get_plugin_name() const {
 	return "ConvertGLTF2";
diff --git a/modules/gridmap/editor/grid_map_editor_plugin.cpp b/modules/gridmap/editor/grid_map_editor_plugin.cpp
index 9eb8cce812..379a08ad9e 100644
--- a/modules/gridmap/editor/grid_map_editor_plugin.cpp
+++ b/modules/gridmap/editor/grid_map_editor_plugin.cpp
@@ -55,6 +55,7 @@
 #include "scene/gui/separator.h"
 #include "scene/gui/slider.h"
 #include "scene/gui/spin_box.h"
+#include "scene/main/scene_tree.h"
 #include "scene/main/window.h"
 #include "servers/rendering/rendering_server.h"
 
diff --git a/modules/interactive_music/editor/audio_stream_interactive_editor_plugin.cpp b/modules/interactive_music/editor/audio_stream_interactive_editor_plugin.cpp
index 5dd0af8eff..b0c9ff94e3 100644
--- a/modules/interactive_music/editor/audio_stream_interactive_editor_plugin.cpp
+++ b/modules/interactive_music/editor/audio_stream_interactive_editor_plugin.cpp
@@ -34,6 +34,7 @@
 
 #include "core/object/callable_mp.h"
 #include "core/object/class_db.h"
+#include "core/object/message_queue.h"
 #include "editor/editor_node.h"
 #include "editor/editor_string_names.h"
 #include "editor/editor_undo_redo_manager.h"
diff --git a/modules/multiplayer/editor/multiplayer_editor_plugin.cpp b/modules/multiplayer/editor/multiplayer_editor_plugin.cpp
index 58dd7e4b05..1dbb5aea16 100644
--- a/modules/multiplayer/editor/multiplayer_editor_plugin.cpp
+++ b/modules/multiplayer/editor/multiplayer_editor_plugin.cpp
@@ -39,6 +39,7 @@
 #include "editor/docks/editor_dock_manager.h"
 #include "editor/editor_interface.h"
 #include "editor/editor_node.h"
+#include "scene/main/scene_tree.h"
 
 void MultiplayerEditorDebugger::_bind_methods() {
 	ADD_SIGNAL(MethodInfo("open_request", PropertyInfo(Variant::STRING, "path")));
diff --git a/modules/navigation_2d/2d/nav_mesh_generator_2d.cpp b/modules/navigation_2d/2d/nav_mesh_generator_2d.cpp
index 89f350ff6d..b954c90b70 100644
--- a/modules/navigation_2d/2d/nav_mesh_generator_2d.cpp
+++ b/modules/navigation_2d/2d/nav_mesh_generator_2d.cpp
@@ -33,6 +33,7 @@
 #include "nav_mesh_generator_2d.h"
 
 #include "core/config/project_settings.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/2d/navigation_mesh_source_geometry_data_2d.h"
 #include "scene/resources/2d/navigation_polygon.h"
 
diff --git a/modules/navigation_2d/editor/navigation_link_2d_editor_plugin.cpp b/modules/navigation_2d/editor/navigation_link_2d_editor_plugin.cpp
index 699e4d31f1..63b79981db 100644
--- a/modules/navigation_2d/editor/navigation_link_2d_editor_plugin.cpp
+++ b/modules/navigation_2d/editor/navigation_link_2d_editor_plugin.cpp
@@ -35,6 +35,7 @@
 #include "editor/editor_undo_redo_manager.h"
 #include "editor/scene/canvas_item_editor_plugin.h"
 #include "editor/settings/editor_settings.h"
+#include "scene/main/scene_tree.h"
 #include "scene/main/viewport.h"
 
 void NavigationLink2DEditor::_notification(int p_what) {
diff --git a/modules/navigation_3d/3d/nav_mesh_generator_3d.cpp b/modules/navigation_3d/3d/nav_mesh_generator_3d.cpp
index bd7e23373b..200794df16 100644
--- a/modules/navigation_3d/3d/nav_mesh_generator_3d.cpp
+++ b/modules/navigation_3d/3d/nav_mesh_generator_3d.cpp
@@ -33,6 +33,7 @@
 #include "core/config/project_settings.h"
 #include "core/os/thread.h"
 #include "scene/3d/node_3d.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/3d/navigation_mesh_source_geometry_data_3d.h"
 #include "scene/resources/navigation_mesh.h"
 
diff --git a/modules/navigation_3d/editor/navigation_obstacle_3d_editor_plugin.cpp b/modules/navigation_3d/editor/navigation_obstacle_3d_editor_plugin.cpp
index 0378b73ee7..59542c2c6e 100644
--- a/modules/navigation_3d/editor/navigation_obstacle_3d_editor_plugin.cpp
+++ b/modules/navigation_3d/editor/navigation_obstacle_3d_editor_plugin.cpp
@@ -41,6 +41,7 @@
 #include "scene/3d/navigation/navigation_obstacle_3d.h"
 #include "scene/gui/button.h"
 #include "scene/gui/dialogs.h"
+#include "scene/main/scene_tree.h"
 #include "servers/navigation_3d/navigation_server_3d.h"
 #include "servers/rendering/rendering_server.h"
 
diff --git a/modules/navigation_3d/editor/navigation_region_3d_editor_plugin.cpp b/modules/navigation_3d/editor/navigation_region_3d_editor_plugin.cpp
index 8d3990ff16..6c84681922 100644
--- a/modules/navigation_3d/editor/navigation_region_3d_editor_plugin.cpp
+++ b/modules/navigation_3d/editor/navigation_region_3d_editor_plugin.cpp
@@ -40,6 +40,7 @@
 #include "scene/gui/button.h"
 #include "scene/gui/dialogs.h"
 #include "scene/gui/label.h"
+#include "scene/main/scene_tree.h"
 #include "servers/navigation_3d/navigation_server_3d.h"
 
 void NavigationRegion3DEditor::_node_removed(Node *p_node) {
diff --git a/modules/objectdb_profiler/editor/data_viewers/refcounted_view.cpp b/modules/objectdb_profiler/editor/data_viewers/refcounted_view.cpp
index 9e698b3d00..8fed31c313 100644
--- a/modules/objectdb_profiler/editor/data_viewers/refcounted_view.cpp
+++ b/modules/objectdb_profiler/editor/data_viewers/refcounted_view.cpp
@@ -35,6 +35,7 @@
 #include "editor/themes/editor_scale.h"
 #include "scene/gui/rich_text_label.h"
 #include "scene/gui/split_container.h"
+#include "scene/main/scene_tree.h"
 
 SnapshotRefCountedView::SnapshotRefCountedView() {
 	set_name(TTRC("RefCounted"));
diff --git a/modules/objectdb_profiler/editor/objectdb_profiler_panel.cpp b/modules/objectdb_profiler/editor/objectdb_profiler_panel.cpp
index 78c7779623..2b69d5a1cf 100644
--- a/modules/objectdb_profiler/editor/objectdb_profiler_panel.cpp
+++ b/modules/objectdb_profiler/editor/objectdb_profiler_panel.cpp
@@ -52,6 +52,7 @@
 #include "scene/gui/option_button.h"
 #include "scene/gui/split_container.h"
 #include "scene/gui/tab_container.h"
+#include "scene/main/scene_tree.h"
 
 // ObjectDB snapshots are very large. In remote_debugger_peer.cpp, the max in_buf and out_buf size is 8mb.
 // Snapshots are typically larger than that, so we send them 6mb at a time. Leaving 2mb for other data.
diff --git a/platform/macos/key_mapping_macos.mm b/platform/macos/key_mapping_macos.mm
index 07cad71895..640598020b 100644
--- a/platform/macos/key_mapping_macos.mm
+++ b/platform/macos/key_mapping_macos.mm
@@ -30,6 +30,7 @@
 
 #import "key_mapping_macos.h"
 
+#include "core/string/ustring.h"
 #include "core/templates/hash_map.h"
 #include "core/templates/hash_set.h"
 
diff --git a/platform/web/audio_driver_web.cpp b/platform/web/audio_driver_web.cpp
index c870554127..22635cfcbe 100644
--- a/platform/web/audio_driver_web.cpp
+++ b/platform/web/audio_driver_web.cpp
@@ -34,6 +34,7 @@
 
 #include "core/config/engine.h"
 #include "core/config/project_settings.h"
+#include "core/math/math_funcs_binary.h"
 #include "core/object/object.h"
 #include "scene/main/node.h"
 #include "servers/audio/audio_stream.h"
diff --git a/scene/2d/camera_2d.cpp b/scene/2d/camera_2d.cpp
index 013f2cbd23..3b3e0f7f78 100644
--- a/scene/2d/camera_2d.cpp
+++ b/scene/2d/camera_2d.cpp
@@ -35,6 +35,7 @@
 #include "core/input/input.h"
 #include "core/object/callable_mp.h"
 #include "core/object/class_db.h"
+#include "scene/main/scene_tree.h"
 #include "scene/main/viewport.h"
 
 void Camera2D::_update_scroll() {
diff --git a/scene/2d/canvas_modulate.cpp b/scene/2d/canvas_modulate.cpp
index 6e1e52efbd..0de9d8a231 100644
--- a/scene/2d/canvas_modulate.cpp
+++ b/scene/2d/canvas_modulate.cpp
@@ -31,6 +31,7 @@
 #include "canvas_modulate.h"
 
 #include "core/object/class_db.h"
+#include "scene/main/scene_tree.h"
 #include "servers/rendering/rendering_server.h"
 
 void CanvasModulate::_on_in_canvas_visibility_changed(bool p_new_visibility) {
diff --git a/scene/2d/cpu_particles_2d.cpp b/scene/2d/cpu_particles_2d.cpp
index f108868003..dfc0768cec 100644
--- a/scene/2d/cpu_particles_2d.cpp
+++ b/scene/2d/cpu_particles_2d.cpp
@@ -37,6 +37,7 @@
 #include "core/object/callable_mp.h"
 #include "core/object/class_db.h"
 #include "scene/2d/gpu_particles_2d.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/atlas_texture.h"
 #include "scene/resources/canvas_item_material.h"
 #include "scene/resources/curve_texture.h"
diff --git a/scene/2d/light_2d.cpp b/scene/2d/light_2d.cpp
index 2091018007..156bced6ae 100644
--- a/scene/2d/light_2d.cpp
+++ b/scene/2d/light_2d.cpp
@@ -32,6 +32,7 @@
 
 #include "core/config/engine.h"
 #include "core/object/class_db.h"
+#include "scene/main/scene_tree.h"
 #include "servers/rendering/rendering_server.h"
 
 void Light2D::owner_changed_notify() {
diff --git a/scene/2d/navigation/navigation_agent_2d.cpp b/scene/2d/navigation/navigation_agent_2d.cpp
index 21fcbeb8c9..2fbb7cac4c 100644
--- a/scene/2d/navigation/navigation_agent_2d.cpp
+++ b/scene/2d/navigation/navigation_agent_2d.cpp
@@ -34,6 +34,7 @@
 #include "core/object/callable_mp.h"
 #include "core/object/class_db.h"
 #include "scene/2d/navigation/navigation_link_2d.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/world_2d.h"
 #include "servers/navigation_2d/navigation_server_2d.h"
 #include "servers/rendering/rendering_server.h"
diff --git a/scene/2d/navigation/navigation_obstacle_2d.cpp b/scene/2d/navigation/navigation_obstacle_2d.cpp
index 7de62154ab..f20e5e7e5a 100644
--- a/scene/2d/navigation/navigation_obstacle_2d.cpp
+++ b/scene/2d/navigation/navigation_obstacle_2d.cpp
@@ -34,6 +34,7 @@
 #include "core/math/geometry_2d.h"
 #include "core/object/callable_mp.h"
 #include "core/object/class_db.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/2d/navigation_mesh_source_geometry_data_2d.h"
 #include "scene/resources/2d/navigation_polygon.h"
 #include "scene/resources/world_2d.h"
diff --git a/scene/2d/navigation/navigation_region_2d.cpp b/scene/2d/navigation/navigation_region_2d.cpp
index f05e287874..91a1ddea7c 100644
--- a/scene/2d/navigation/navigation_region_2d.cpp
+++ b/scene/2d/navigation/navigation_region_2d.cpp
@@ -34,6 +34,7 @@
 #include "core/math/random_pcg.h"
 #include "core/object/callable_mp.h"
 #include "core/object/class_db.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/world_2d.h"
 #include "servers/navigation_2d/navigation_server_2d.h"
 #include "servers/rendering/rendering_server.h"
diff --git a/scene/2d/physics/collision_polygon_2d.cpp b/scene/2d/physics/collision_polygon_2d.cpp
index 5e58d2cc7e..61bcedadc5 100644
--- a/scene/2d/physics/collision_polygon_2d.cpp
+++ b/scene/2d/physics/collision_polygon_2d.cpp
@@ -35,6 +35,7 @@
 #include "core/object/class_db.h"
 #include "scene/2d/physics/area_2d.h"
 #include "scene/2d/physics/collision_object_2d.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/2d/concave_polygon_shape_2d.h"
 #include "scene/resources/2d/convex_polygon_shape_2d.h"
 
diff --git a/scene/2d/physics/joints/damped_spring_joint_2d.cpp b/scene/2d/physics/joints/damped_spring_joint_2d.cpp
index 3ea4b2e21b..9af1ff85ce 100644
--- a/scene/2d/physics/joints/damped_spring_joint_2d.cpp
+++ b/scene/2d/physics/joints/damped_spring_joint_2d.cpp
@@ -33,6 +33,7 @@
 #include "core/config/engine.h"
 #include "core/object/class_db.h"
 #include "scene/2d/physics/physics_body_2d.h"
+#include "scene/main/scene_tree.h"
 
 void DampedSpringJoint2D::_notification(int p_what) {
 	switch (p_what) {
diff --git a/scene/2d/physics/joints/groove_joint_2d.cpp b/scene/2d/physics/joints/groove_joint_2d.cpp
index 40c89ed98c..f2e7a06ff7 100644
--- a/scene/2d/physics/joints/groove_joint_2d.cpp
+++ b/scene/2d/physics/joints/groove_joint_2d.cpp
@@ -33,6 +33,7 @@
 #include "core/config/engine.h"
 #include "core/object/class_db.h"
 #include "scene/2d/physics/physics_body_2d.h"
+#include "scene/main/scene_tree.h"
 
 void GrooveJoint2D::_notification(int p_what) {
 	switch (p_what) {
diff --git a/scene/2d/physics/joints/pin_joint_2d.cpp b/scene/2d/physics/joints/pin_joint_2d.cpp
index 193991419c..400a9da2ea 100644
--- a/scene/2d/physics/joints/pin_joint_2d.cpp
+++ b/scene/2d/physics/joints/pin_joint_2d.cpp
@@ -33,6 +33,7 @@
 #include "core/config/engine.h"
 #include "core/object/class_db.h"
 #include "scene/2d/physics/physics_body_2d.h"
+#include "scene/main/scene_tree.h"
 
 void PinJoint2D::_notification(int p_what) {
 	switch (p_what) {
diff --git a/scene/2d/physics/ray_cast_2d.cpp b/scene/2d/physics/ray_cast_2d.cpp
index 7244068601..abfd314764 100644
--- a/scene/2d/physics/ray_cast_2d.cpp
+++ b/scene/2d/physics/ray_cast_2d.cpp
@@ -33,6 +33,7 @@
 #include "core/config/engine.h"
 #include "core/object/class_db.h"
 #include "scene/2d/physics/collision_object_2d.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/world_2d.h"
 
 void RayCast2D::set_target_position(const Vector2 &p_point) {
diff --git a/scene/2d/physics/shape_cast_2d.cpp b/scene/2d/physics/shape_cast_2d.cpp
index b81df9c5c5..2d1dba7336 100644
--- a/scene/2d/physics/shape_cast_2d.cpp
+++ b/scene/2d/physics/shape_cast_2d.cpp
@@ -34,6 +34,7 @@
 #include "core/object/callable_mp.h"
 #include "core/object/class_db.h"
 #include "scene/2d/physics/collision_object_2d.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/world_2d.h"
 #include "servers/physics_2d/physics_server_2d.h"
 
diff --git a/scene/2d/physics/touch_screen_button.cpp b/scene/2d/physics/touch_screen_button.cpp
index 3bf6b2e81f..3693910638 100644
--- a/scene/2d/physics/touch_screen_button.cpp
+++ b/scene/2d/physics/touch_screen_button.cpp
@@ -34,6 +34,7 @@
 #include "core/input/input.h"
 #include "core/object/callable_mp.h"
 #include "core/object/class_db.h"
+#include "scene/main/scene_tree.h"
 #include "scene/main/viewport.h"
 #include "servers/display/accessibility_server.h"
 #include "servers/display/display_server.h"
diff --git a/scene/3d/light_3d.cpp b/scene/3d/light_3d.cpp
index bb45757961..91ee328e72 100644
--- a/scene/3d/light_3d.cpp
+++ b/scene/3d/light_3d.cpp
@@ -34,6 +34,7 @@
 #include "core/config/project_settings.h"
 #include "core/object/class_db.h"
 #include "core/os/os.h"
+#include "scene/main/scene_tree.h"
 #include "servers/rendering/rendering_server.h"
 
 void Light3D::set_param(Param p_param, real_t p_value) {
diff --git a/scene/3d/mesh_instance_3d.cpp b/scene/3d/mesh_instance_3d.cpp
index 6e2380d0eb..e3141d6c88 100644
--- a/scene/3d/mesh_instance_3d.cpp
+++ b/scene/3d/mesh_instance_3d.cpp
@@ -33,6 +33,7 @@
 #include "core/object/callable_mp.h"
 #include "core/object/class_db.h"
 #include "scene/3d/skeleton_3d.h"
+#include "scene/main/scene_tree.h"
 
 #ifndef PHYSICS_3D_DISABLED
 #include "scene/3d/physics/collision_shape_3d.h"
diff --git a/scene/3d/navigation/navigation_agent_3d.cpp b/scene/3d/navigation/navigation_agent_3d.cpp
index 9603a254e2..900811186c 100644
--- a/scene/3d/navigation/navigation_agent_3d.cpp
+++ b/scene/3d/navigation/navigation_agent_3d.cpp
@@ -34,6 +34,7 @@
 #include "core/object/callable_mp.h"
 #include "core/object/class_db.h"
 #include "scene/3d/navigation/navigation_link_3d.h"
+#include "scene/main/scene_tree.h"
 #include "servers/navigation_3d/navigation_server_3d.h"
 #include "servers/rendering/rendering_server.h"
 
diff --git a/scene/3d/navigation/navigation_agent_3d.h b/scene/3d/navigation/navigation_agent_3d.h
index 03a92b7bc7..7d6a55477b 100644
--- a/scene/3d/navigation/navigation_agent_3d.h
+++ b/scene/3d/navigation/navigation_agent_3d.h
@@ -35,6 +35,7 @@
 #include "servers/navigation_3d/navigation_path_query_parameters_3d.h"
 #include "servers/navigation_3d/navigation_path_query_result_3d.h"
 
+class ArrayMesh;
 class Node3D;
 class StandardMaterial3D;
 
diff --git a/scene/3d/navigation/navigation_link_3d.h b/scene/3d/navigation/navigation_link_3d.h
index ff0c371251..23aeadff60 100644
--- a/scene/3d/navigation/navigation_link_3d.h
+++ b/scene/3d/navigation/navigation_link_3d.h
@@ -32,6 +32,8 @@
 
 #include "scene/3d/node_3d.h"
 
+class ArrayMesh;
+
 class NavigationLink3D : public Node3D {
 	GDCLASS(NavigationLink3D, Node3D);
 
diff --git a/scene/3d/navigation/navigation_obstacle_3d.cpp b/scene/3d/navigation/navigation_obstacle_3d.cpp
index 94bd5f7d6a..7e988c63c8 100644
--- a/scene/3d/navigation/navigation_obstacle_3d.cpp
+++ b/scene/3d/navigation/navigation_obstacle_3d.cpp
@@ -34,6 +34,7 @@
 #include "core/math/geometry_2d.h"
 #include "core/object/callable_mp.h"
 #include "core/object/class_db.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/3d/navigation_mesh_source_geometry_data_3d.h"
 #include "scene/resources/navigation_mesh.h"
 #include "servers/navigation_3d/navigation_server_3d.h"
diff --git a/scene/3d/node_3d.h b/scene/3d/node_3d.h
index 59cbca06ca..9f77c699e3 100644
--- a/scene/3d/node_3d.h
+++ b/scene/3d/node_3d.h
@@ -31,7 +31,6 @@
 #pragma once
 
 #include "scene/main/node.h"
-#include "scene/main/scene_tree.h"
 #include "scene/resources/3d/world_3d.h"
 
 class Node3DGizmo : public RefCounted {
@@ -233,7 +232,7 @@ protected:
 
 public:
 	enum {
-		NOTIFICATION_TRANSFORM_CHANGED = SceneTree::NOTIFICATION_TRANSFORM_CHANGED,
+		NOTIFICATION_TRANSFORM_CHANGED = 2000, // Keep in sync with SceneTree.
 		NOTIFICATION_ENTER_WORLD = 41,
 		NOTIFICATION_EXIT_WORLD = 42,
 		NOTIFICATION_VISIBILITY_CHANGED = 43,
diff --git a/scene/3d/occluder_instance_3d.h b/scene/3d/occluder_instance_3d.h
index 1078317f9e..4c040c9787 100644
--- a/scene/3d/occluder_instance_3d.h
+++ b/scene/3d/occluder_instance_3d.h
@@ -32,6 +32,8 @@
 
 #include "scene/3d/visual_instance_3d.h"
 
+class ArrayMesh;
+
 class Occluder3D : public Resource {
 	GDCLASS(Occluder3D, Resource);
 	RES_BASE_EXTENSION("occ");
diff --git a/scene/3d/path_3d.h b/scene/3d/path_3d.h
index be7e5e3db9..bd073083b2 100644
--- a/scene/3d/path_3d.h
+++ b/scene/3d/path_3d.h
@@ -34,6 +34,8 @@
 #include "scene/resources/curve.h"
 #include "scene/resources/material.h"
 
+class ArrayMesh;
+
 class Path3D : public Node3D {
 	GDCLASS(Path3D, Node3D);
 
diff --git a/scene/3d/physics/collision_object_3d.cpp b/scene/3d/physics/collision_object_3d.cpp
index 90559334ab..88cf223fad 100644
--- a/scene/3d/physics/collision_object_3d.cpp
+++ b/scene/3d/physics/collision_object_3d.cpp
@@ -33,6 +33,7 @@
 #include "core/config/engine.h"
 #include "core/object/callable_mp.h"
 #include "core/object/class_db.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/3d/shape_3d.h"
 #include "scene/resources/mesh.h"
 #include "servers/rendering/rendering_server.h"
diff --git a/scene/3d/physics/ray_cast_3d.cpp b/scene/3d/physics/ray_cast_3d.cpp
index c70bf2ed49..51d1d7c525 100644
--- a/scene/3d/physics/ray_cast_3d.cpp
+++ b/scene/3d/physics/ray_cast_3d.cpp
@@ -33,6 +33,7 @@
 #include "core/config/engine.h"
 #include "core/object/class_db.h"
 #include "scene/3d/physics/collision_object_3d.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/mesh.h"
 #include "servers/rendering/rendering_server.h"
 
diff --git a/scene/3d/physics/ray_cast_3d.h b/scene/3d/physics/ray_cast_3d.h
index 1c467f0531..5a1c4dc6b3 100644
--- a/scene/3d/physics/ray_cast_3d.h
+++ b/scene/3d/physics/ray_cast_3d.h
@@ -33,6 +33,7 @@
 #include "scene/3d/node_3d.h"
 #include "scene/resources/material.h"
 
+class ArrayMesh;
 class CollisionObject3D;
 
 class RayCast3D : public Node3D {
diff --git a/scene/3d/physics/shape_cast_3d.cpp b/scene/3d/physics/shape_cast_3d.cpp
index a75c9d0cea..e2cedb40b0 100644
--- a/scene/3d/physics/shape_cast_3d.cpp
+++ b/scene/3d/physics/shape_cast_3d.cpp
@@ -34,6 +34,7 @@
 #include "core/object/callable_mp.h"
 #include "core/object/class_db.h"
 #include "scene/3d/physics/collision_object_3d.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/3d/concave_polygon_shape_3d.h"
 #include "scene/resources/mesh.h"
 #include "servers/rendering/rendering_server.h"
diff --git a/scene/3d/physics/spring_arm_3d.cpp b/scene/3d/physics/spring_arm_3d.cpp
index bad2f59623..878fddec7f 100644
--- a/scene/3d/physics/spring_arm_3d.cpp
+++ b/scene/3d/physics/spring_arm_3d.cpp
@@ -33,6 +33,7 @@
 #include "core/config/engine.h"
 #include "core/object/class_db.h"
 #include "scene/3d/camera_3d.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/3d/shape_3d.h"
 
 void SpringArm3D::_notification(int p_what) {
diff --git a/scene/3d/visual_instance_3d.cpp b/scene/3d/visual_instance_3d.cpp
index 505d5aaffa..86bb3d1740 100644
--- a/scene/3d/visual_instance_3d.cpp
+++ b/scene/3d/visual_instance_3d.cpp
@@ -36,6 +36,7 @@ STATIC_ASSERT_INCOMPLETE_TYPE(class, RenderingServer);
 #include "core/object/callable_mp.h"
 #include "core/object/class_db.h"
 #include "core/os/os.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/material.h"
 #include "servers/rendering/rendering_server.h"
 
diff --git a/scene/3d/visual_instance_3d.h b/scene/3d/visual_instance_3d.h
index 3e7b671aaa..48e26e0c7d 100644
--- a/scene/3d/visual_instance_3d.h
+++ b/scene/3d/visual_instance_3d.h
@@ -33,6 +33,7 @@
 #include "scene/3d/node_3d.h"
 #include "servers/rendering/rendering_server_enums.h"
 
+class Material;
 class TriangleMesh;
 
 class VisualInstance3D : public Node3D {
diff --git a/scene/3d/voxel_gi.cpp b/scene/3d/voxel_gi.cpp
index e13531d375..fc091b30e5 100644
--- a/scene/3d/voxel_gi.cpp
+++ b/scene/3d/voxel_gi.cpp
@@ -36,6 +36,7 @@
 #include "scene/3d/mesh_instance_3d.h"
 #include "scene/3d/multimesh_instance_3d.h"
 #include "scene/3d/voxelizer.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/camera_attributes.h"
 #include "servers/rendering/rendering_server.h"
 
diff --git a/scene/animation/animation_mixer.cpp b/scene/animation/animation_mixer.cpp
index fe103534f8..436dfbc13e 100644
--- a/scene/animation/animation_mixer.cpp
+++ b/scene/animation/animation_mixer.cpp
@@ -2489,7 +2489,7 @@ void AnimationMixer::_bind_methods() {
 }
 
 AnimationMixer::AnimationMixer() {
-	root_node = SceneStringName(path_pp);
+	root_node = NodePath("..");
 }
 
 AnimationMixer::~AnimationMixer() {
diff --git a/scene/animation/animation_player.cpp b/scene/animation/animation_player.cpp
index 5d1400573d..c87ce8404e 100644
--- a/scene/animation/animation_player.cpp
+++ b/scene/animation/animation_player.cpp
@@ -35,6 +35,7 @@
 #include "core/object/callable_mp.h"
 #include "core/object/class_db.h"
 #include "core/os/os.h"
+#include "scene/main/scene_tree.h"
 
 bool AnimationPlayer::_set(const StringName &p_name, const Variant &p_value) {
 	String name = p_name;
diff --git a/scene/animation/animation_tree.cpp b/scene/animation/animation_tree.cpp
index 9de9abfe0b..d5cecba78c 100644
--- a/scene/animation/animation_tree.cpp
+++ b/scene/animation/animation_tree.cpp
@@ -848,7 +848,7 @@ void AnimationTree::_notification(int p_what) {
 void AnimationTree::set_animation_player(const NodePath &p_path) {
 	animation_player = p_path;
 	if (p_path.is_empty()) {
-		set_root_node(SceneStringName(path_pp));
+		set_root_node(NodePath(".."));
 		while (animation_libraries.size()) {
 			remove_animation_library(animation_libraries[0].name);
 		}
diff --git a/scene/animation/tween.cpp b/scene/animation/tween.cpp
index 86abba1a4e..9e0d7a2223 100644
--- a/scene/animation/tween.cpp
+++ b/scene/animation/tween.cpp
@@ -33,6 +33,7 @@
 #include "core/object/class_db.h"
 #include "scene/animation/easing_equations.h"
 #include "scene/main/node.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/animation.h"
 
 #define CHECK_VALID() \
diff --git a/scene/audio/audio_stream_player_internal.cpp b/scene/audio/audio_stream_player_internal.cpp
index adac5c96a8..133d16c78b 100644
--- a/scene/audio/audio_stream_player_internal.cpp
+++ b/scene/audio/audio_stream_player_internal.cpp
@@ -33,6 +33,7 @@
 #include "core/config/engine.h"
 #include "core/object/callable_mp.h"
 #include "scene/main/node.h"
+#include "scene/main/scene_tree.h"
 #include "servers/audio/audio_stream.h"
 
 void AudioStreamPlayerInternal::_set_process(bool p_enabled) {
diff --git a/scene/gui/color_picker.cpp b/scene/gui/color_picker.cpp
index a3329ed2ca..df8a005e62 100644
--- a/scene/gui/color_picker.cpp
+++ b/scene/gui/color_picker.cpp
@@ -51,6 +51,7 @@
 #include "scene/gui/slider.h"
 #include "scene/gui/spin_box.h"
 #include "scene/gui/texture_rect.h"
+#include "scene/main/scene_tree.h"
 #include "scene/resources/atlas_texture.h"
 #include "scene/resources/color_palette.h"
 #include "scene/resources/image_texture.h"
diff --git a/scene/gui/control.cpp b/scene/gui/control.cpp
index baed743fe8..2586cabdd0 100644
--- a/scene/gui/control.cpp
+++ b/scene/gui/control.cpp
@@ -44,6 +44,7 @@ STATIC_ASSERT_INCOMPLETE_TYPE(class, RenderingServer);
 #include "scene/gui/container.h"
 #include "scene/gui/scroll_container.h"
 #include "scene/main/canvas_layer.h"
+#include "scene/main/scene_tree.h"
 #include "scene/main/window.h"
 #include "scene/theme/theme_db.h"
 #include "scene/theme/theme_owner.h"
diff --git a/scene/gui/graph_node.cpp b/scene/gui/graph_node.cpp
index 599d7ae3e8..0e07326fbc 100644
--- a/scene/gui/graph_node.cpp
+++ b/scene/gui/graph_node.cpp
@@ -35,6 +35,7 @@
 #include "scene/gui/box_container.h"
 #include "scene/gui/graph_edit.h"
 #include "scene/gui/label.h"
+#include "scene/main/scene_tree.h"
 #include "scene/theme/theme_db.h"
 #include "servers/display/accessibility_server.h"
 
diff --git a/scene/gui/label.cpp b/scene/gui/label.cpp
index 1f4f09af75..9366834a43 100644
--- a/scene/gui/label.cpp
+++ b/scene/gui/label.cpp
@@ -33,6 +33,7 @@
 #include "core/object/callable_mp.h"
 #include "core/object/class_db.h"
 #include "scene/gui/container.h"
+#include "scene/main/scene_tree.h"
 #include "scene/theme/theme_db.h"
 #include "servers/display/accessibility_server.h"
 #include "servers/rendering/rendering_server.h"
diff --git a/scene/gui/line_edit.cpp b/scene/gui/line_edit.cpp
index f3db9b7691..7efded00e2 100644
--- a/scene/gui/line_edit.cpp
+++ b/scene/gui/line_edit.cpp
@@ -38,6 +38,7 @@
 #include "core/object/callable_mp.h"
 #include "core/object/class_db.h"
 #include "core/os/keyboard.h"
+#include "core/os/main_loop.h"
 #include "core/os/os.h"
 #include "core/string/alt_codes.h"
 #include "core/string/translation_server.h"
diff --git a/scene/gui/rich_text_label.cpp b/scene/gui/rich_text_label.cpp
index 2bc1cdeb3f..a98609943d 100644
--- a/scene/gui/rich_text_label.cpp
+++ b/scene/gui/rich_text_label.cpp
@@ -43,6 +43,7 @@
 #include "scene/gui/popup_menu.h"
 #include "scene/gui/rich_text_effect.h"
 #include "scene/gui/scroll_bar.h"
+#include "scene/main/scene_tree.h"
 #include "scene/main/timer.h"
 #include "scene/resources/atlas_texture.h"
 #include "scene/resources/text_paragraph.h"
diff --git a/scene/gui/text_edit.cpp b/scene/gui/text_edit.cpp
index 9cae3825fc..76b4c232b3 100644
--- a/scene/gui/text_edit.cpp
+++ b/scene/gui/text_edit.cpp
@@ -39,6 +39,7 @@
 #include "core/object/class_db.h"
 #include "core/object/script_language.h"
 #include "core/os/keyboard.h"
+#include "core/os/main_loop.h"
 #include "core/os/os.h"
 #include "core/string/alt_codes.h"
 #include "core/string/string_builder.h"
diff --git a/scene/gui/tree.cpp b/scene/gui/tree.cpp
index 6282ecc8a7..93cfbf2239 100644
--- a/scene/gui/tree.cpp
+++ b/scene/gui/tree.cpp
@@ -44,6 +44,7 @@
 #include "scene/gui/scroll_bar.h"
 #include "scene/gui/slider.h"
 #include "scene/gui/text_edit.h"
+#include "scene/main/scene_tree.h"
 #include "scene/main/timer.h"
 #include "scene/main/window.h"
 #include "scene/theme/theme_db.h"
diff --git a/scene/gui/video_stream_player.cpp b/scene/gui/video_stream_player.cpp
index 39bda2d3c5..19e0479659 100644
--- a/scene/gui/video_stream_player.cpp
+++ b/scene/gui/video_stream_player.cpp
@@ -33,6 +33,7 @@
 #include "core/config/engine.h"
 #include "core/object/callable_mp.h"
 #include "core/object/class_db.h"
+#include "scene/main/scene_tree.h"
 #include "servers/audio/audio_server.h"
 #include "servers/display/accessibility_server.h"
 
diff --git a/scene/main/canvas_item.cpp b/scene/main/canvas_item.cpp
index 8982d04a4c..cbe8758492 100644
--- a/scene/main/canvas_item.cpp
+++ b/scene/main/canvas_item.cpp
@@ -41,6 +41,7 @@ STATIC_ASSERT_INCOMPLETE_TYPE(class, RenderingServer);
 #include "scene/main/window.h"
 #include "scene/resources/atlas_texture.h"
 #include "scene/resources/font.h"
+#include "scene/resources/material.h"
 #include "scene/resources/mesh.h"
 #include "scene/resources/multimesh.h"
 #include "scene/resources/style_box.h"
diff --git a/scene/main/canvas_item.h b/scene/main/canvas_item.h
index aac64576f9..9dd741a0d9 100644
--- a/scene/main/canvas_item.h
+++ b/scene/main/canvas_item.h
@@ -31,13 +31,13 @@
 #pragma once
 
 #include "scene/main/node.h"
-#include "scene/main/scene_tree.h"
 #include "scene/resources/texture.h"
 #include "servers/rendering/rendering_server_enums.h"
 #include "servers/text/text_server.h"
 
 class CanvasLayer;
 class Font;
+class Material;
 class Mesh;
 class MultiMesh;
 class StyleBox;
@@ -211,7 +211,7 @@ protected:
 
 public:
 	enum {
-		NOTIFICATION_TRANSFORM_CHANGED = SceneTree::NOTIFICATION_TRANSFORM_CHANGED, //unique
+		NOTIFICATION_TRANSFORM_CHANGED = 2000, // Keep in sync with SceneTree.
 		NOTIFICATION_DRAW = 30,
 		NOTIFICATION_VISIBILITY_CHANGED = 31,
 		NOTIFICATION_ENTER_CANVAS = 32,
diff --git a/scene/main/node.cpp b/scene/main/node.cpp
index 983397b6ee..6a2df1ae75 100644
--- a/scene/main/node.cpp
+++ b/scene/main/node.cpp
@@ -49,6 +49,7 @@ STATIC_ASSERT_INCOMPLETE_TYPE(class, Engine);
 #include "scene/animation/tween.h"
 #include "scene/main/instance_placeholder.h"
 #include "scene/main/multiplayer_api.h"
+#include "scene/main/scene_tree.h"
 #include "scene/main/viewport.h"
 #include "scene/main/window.h"
 #include "scene/resources/packed_scene.h"
@@ -971,6 +972,10 @@ void Node::set_physics_interpolation_mode(PhysicsInterpolationMode p_mode) {
 	}
 }
 
+bool Node::is_physics_interpolated_and_enabled() const {
+	return SceneTree::is_fti_enabled() && is_physics_interpolated();
+}
+
 void Node::reset_physics_interpolation() {
 	if (SceneTree::is_fti_enabled() && is_inside_tree()) {
 		propagate_notification(NOTIFICATION_RESET_PHYSICS_INTERPOLATION);
diff --git a/scene/main/node.h b/scene/main/node.h
index 0be4f94c62..a06bd7dedb 100644
--- a/scene/main/node.h
+++ b/scene/main/node.h
@@ -31,19 +31,21 @@
 #pragma once
 
 #include "core/input/input_event.h"
+#include "core/object/gdvirtual.gen.h"
 #include "core/object/object.h"
 #include "core/object/ref_counted.h"
-#include "core/string/node_path.h"
 #include "core/templates/iterable.h"
-#include "core/variant/typed_array.h"
-#include "scene/main/scene_tree.h"
 #include "scene/scene_string_names.h"
 
+class MultiplayerAPI;
+class NodePath;
 class Resource;
 class SceneState;
+class SceneTree;
 class Tween;
 class Viewport;
 class Window;
+struct SceneTreeGroup;
 
 SAFE_FLAG_TYPE_PUN_GUARANTEES
 SAFE_NUMERIC_TYPE_PUN_GUARANTEES(uint32_t)
@@ -169,7 +171,7 @@ public:
 private:
 	struct GroupData {
 		bool persistent = false;
-		SceneTree::Group *group = nullptr;
+		SceneTreeGroup *group = nullptr;
 	};
 
 	struct ComparatorByIndex {
@@ -485,16 +487,17 @@ public:
 		NOTIFICATION_VP_MOUSE_EXIT = 1011,
 		NOTIFICATION_WM_POSITION_CHANGED = 1012,
 
-		NOTIFICATION_OS_MEMORY_WARNING = MainLoop::NOTIFICATION_OS_MEMORY_WARNING,
-		NOTIFICATION_TRANSLATION_CHANGED = MainLoop::NOTIFICATION_TRANSLATION_CHANGED,
-		NOTIFICATION_WM_ABOUT = MainLoop::NOTIFICATION_WM_ABOUT,
-		NOTIFICATION_CRASH = MainLoop::NOTIFICATION_CRASH,
-		NOTIFICATION_OS_IME_UPDATE = MainLoop::NOTIFICATION_OS_IME_UPDATE,
-		NOTIFICATION_APPLICATION_RESUMED = MainLoop::NOTIFICATION_APPLICATION_RESUMED,
-		NOTIFICATION_APPLICATION_PAUSED = MainLoop::NOTIFICATION_APPLICATION_PAUSED,
-		NOTIFICATION_APPLICATION_FOCUS_IN = MainLoop::NOTIFICATION_APPLICATION_FOCUS_IN,
-		NOTIFICATION_APPLICATION_FOCUS_OUT = MainLoop::NOTIFICATION_APPLICATION_FOCUS_OUT,
-		NOTIFICATION_TEXT_SERVER_CHANGED = MainLoop::NOTIFICATION_TEXT_SERVER_CHANGED,
+		// Keep these in sync with MainLoop.
+		NOTIFICATION_OS_MEMORY_WARNING = 2009,
+		NOTIFICATION_TRANSLATION_CHANGED = 2010,
+		NOTIFICATION_WM_ABOUT = 2011,
+		NOTIFICATION_CRASH = 2012,
+		NOTIFICATION_OS_IME_UPDATE = 2013,
+		NOTIFICATION_APPLICATION_RESUMED = 2014,
+		NOTIFICATION_APPLICATION_PAUSED = 2015,
+		NOTIFICATION_APPLICATION_FOCUS_IN = 2016,
+		NOTIFICATION_APPLICATION_FOCUS_OUT = 2017,
+		NOTIFICATION_TEXT_SERVER_CHANGED = 2018,
 
 		// Editor specific node notifications
 		NOTIFICATION_EDITOR_PRE_SAVE = 9001,
@@ -751,7 +754,7 @@ public:
 	void set_physics_interpolation_mode(PhysicsInterpolationMode p_mode);
 	PhysicsInterpolationMode get_physics_interpolation_mode() const { return data.physics_interpolation_mode; }
 	_FORCE_INLINE_ bool is_physics_interpolated() const { return data.physics_interpolated; }
-	_FORCE_INLINE_ bool is_physics_interpolated_and_enabled() const { return SceneTree::is_fti_enabled() && is_physics_interpolated(); }
+	bool is_physics_interpolated_and_enabled() const;
 	void reset_physics_interpolation();
 
 	bool is_enabled() const;
diff --git a/scene/main/scene_tree.cpp b/scene/main/scene_tree.cpp
index 44ec0f7770..994a474bfe 100644
--- a/scene/main/scene_tree.cpp
+++ b/scene/main/scene_tree.cpp
@@ -39,7 +39,6 @@ STATIC_ASSERT_INCOMPLETE_TYPE(class, RenderingServer);
 #include "core/io/resource_loader.h"
 #include "core/object/callable_mp.h"
 #include "core/object/class_db.h"
-#include "core/object/message_queue.h"
 #include "core/object/worker_thread_pool.h"
 #include "core/os/os.h"
 #include "core/profiling/profiling.h"
@@ -172,12 +171,12 @@ void SceneTree::node_renamed(Node *p_node) {
 	emit_signal(node_renamed_name, p_node);
 }
 
-SceneTree::Group *SceneTree::add_to_group(const StringName &p_group, Node *p_node) {
+SceneTreeGroup *SceneTree::add_to_group(const StringName &p_group, Node *p_node) {
 	_THREAD_SAFE_METHOD_
 
-	HashMap<StringName, Group>::Iterator E = group_map.find(p_group);
+	HashMap<StringName, SceneTreeGroup>::Iterator E = group_map.find(p_group);
 	if (!E) {
-		E = group_map.insert(p_group, Group());
+		E = group_map.insert(p_group, SceneTreeGroup());
 	}
 
 	ERR_FAIL_COND_V_MSG(E->value.nodes.has(p_node), &E->value, "Already in group: " + p_group + ".");
@@ -189,7 +188,7 @@ SceneTree::Group *SceneTree::add_to_group(const StringName &p_group, Node *p_nod
 void SceneTree::remove_from_group(const StringName &p_group, Node *p_node) {
 	_THREAD_SAFE_METHOD_
 
-	HashMap<StringName, Group>::Iterator E = group_map.find(p_group);
+	HashMap<StringName, SceneTreeGroup>::Iterator E = group_map.find(p_group);
 	ERR_FAIL_COND(!E);
 
 	E->value.nodes.erase(p_node);
@@ -338,7 +337,7 @@ void SceneTree::_flush_ugc() {
 	ugc_locked = false;
 }
 
-void SceneTree::_update_group_order(Group &g) {
+void SceneTree::_update_group_order(SceneTreeGroup &g) {
 	if (!g.changed) {
 		return;
 	}
@@ -361,11 +360,11 @@ void SceneTree::call_group_flagsp(uint32_t p_call_flags, const StringName &p_gro
 	{
 		_THREAD_SAFE_METHOD_
 
-		HashMap<StringName, Group>::Iterator E = group_map.find(p_group);
+		HashMap<StringName, SceneTreeGroup>::Iterator E = group_map.find(p_group);
 		if (!E) {
 			return;
 		}
-		Group &g = E->value;
+		SceneTreeGroup &g = E->value;
 		if (g.nodes.is_empty()) {
 			return;
 		}
@@ -452,11 +451,11 @@ void SceneTree::notify_group_flags(uint32_t p_call_flags, const StringName &p_gr
 	Vector<Node *> nodes_copy;
 	{
 		_THREAD_SAFE_METHOD_
-		HashMap<StringName, Group>::Iterator E = group_map.find(p_group);
+		HashMap<StringName, SceneTreeGroup>::Iterator E = group_map.find(p_group);
 		if (!E) {
 			return;
 		}
-		Group &g = E->value;
+		SceneTreeGroup &g = E->value;
 		if (g.nodes.is_empty()) {
 			return;
 		}
@@ -515,11 +514,11 @@ void SceneTree::set_group_flags(uint32_t p_call_flags, const StringName &p_group
 	{
 		_THREAD_SAFE_METHOD_
 
-		HashMap<StringName, Group>::Iterator E = group_map.find(p_group);
+		HashMap<StringName, SceneTreeGroup>::Iterator E = group_map.find(p_group);
 		if (!E) {
 			return;
 		}
-		Group &g = E->value;
+		SceneTreeGroup &g = E->value;
 		if (g.nodes.is_empty()) {
 			return;
 		}
@@ -1426,11 +1425,11 @@ void SceneTree::_call_input_pause(const StringName &p_group, CallInputType p_cal
 	{
 		_THREAD_SAFE_METHOD_
 
-		HashMap<StringName, Group>::Iterator E = group_map.find(p_group);
+		HashMap<StringName, SceneTreeGroup>::Iterator E = group_map.find(p_group);
 		if (!E) {
 			return;
 		}
-		Group &g = E->value;
+		SceneTreeGroup &g = E->value;
 		if (g.nodes.is_empty()) {
 			return;
 		}
@@ -1549,7 +1548,7 @@ int64_t SceneTree::get_frame() const {
 TypedArray<Node> SceneTree::_get_nodes_in_group(const StringName &p_group) {
 	_THREAD_SAFE_METHOD_
 	TypedArray<Node> ret;
-	HashMap<StringName, Group>::Iterator E = group_map.find(p_group);
+	HashMap<StringName, SceneTreeGroup>::Iterator E = group_map.find(p_group);
 	if (!E) {
 		return ret;
 	}
@@ -1577,7 +1576,7 @@ bool SceneTree::has_group(const StringName &p_identifier) const {
 
 int SceneTree::get_node_count_in_group(const StringName &p_group) const {
 	_THREAD_SAFE_METHOD_
-	HashMap<StringName, Group>::ConstIterator E = group_map.find(p_group);
+	HashMap<StringName, SceneTreeGroup>::ConstIterator E = group_map.find(p_group);
 	if (!E) {
 		return 0;
 	}
@@ -1587,7 +1586,7 @@ int SceneTree::get_node_count_in_group(const StringName &p_group) const {
 
 Node *SceneTree::get_first_node_in_group(const StringName &p_group) {
 	_THREAD_SAFE_METHOD_
-	HashMap<StringName, Group>::Iterator E = group_map.find(p_group);
+	HashMap<StringName, SceneTreeGroup>::Iterator E = group_map.find(p_group);
 	if (!E) {
 		return nullptr; // No group.
 	}
@@ -1603,7 +1602,7 @@ Node *SceneTree::get_first_node_in_group(const StringName &p_group) {
 
 Vector<Node *> SceneTree::get_nodes_in_group(const StringName &p_group) {
 	_THREAD_SAFE_METHOD_
-	HashMap<StringName, Group>::Iterator E = group_map.find(p_group);
+	HashMap<StringName, SceneTreeGroup>::Iterator E = group_map.find(p_group);
 	if (!E) {
 		return {};
 	}
diff --git a/scene/main/scene_tree.h b/scene/main/scene_tree.h
index 2887960142..b3a3757a17 100644
--- a/scene/main/scene_tree.h
+++ b/scene/main/scene_tree.h
@@ -81,6 +81,11 @@ public:
 	void release_connections();
 };
 
+struct SceneTreeGroup {
+	Vector<Node *> nodes;
+	bool changed = false;
+};
+
 class SceneTree : public MainLoop {
 	_THREAD_SAFE_CLASS_
 
@@ -118,11 +123,6 @@ private:
 
 	bool node_threading_disabled = false;
 
-	struct Group {
-		Vector<Node *> nodes;
-		bool changed = false;
-	};
-
 #ifndef _3D_DISABLED
 	struct ClientPhysicsInterpolation {
 		SelfList<Node3D>::List _node_3d_list;
@@ -145,7 +145,7 @@ private:
 	bool paused = false;
 	bool suspended = false;
 
-	HashMap<StringName, Group> group_map;
+	HashMap<StringName, SceneTreeGroup> group_map;
 	bool _quit = false;
 
 	// Static so we can get directly instead of via SceneTree pointer.
@@ -196,7 +196,7 @@ private:
 	bool ugc_locked = false;
 	void _flush_ugc();
 
-	_FORCE_INLINE_ void _update_group_order(Group &g);
+	_FORCE_INLINE_ void _update_group_order(SceneTreeGroup &g);
 
 	TypedArray<Node> _get_nodes_in_group(const StringName &p_group);
 
@@ -234,7 +234,7 @@ private:
 	void process_timers(double p_delta, bool p_physics_frame);
 	void process_tweens(double p_delta, bool p_physics_frame);
 
-	Group *add_to_group(const StringName &p_group, Node *p_node);
+	SceneTreeGroup *add_to_group(const StringName &p_group, Node *p_node);
 	void remove_from_group(const StringName &p_group, Node *p_node);
 
 	void _process_group(ProcessGroup *p_group, bool p_physics);
@@ -289,6 +289,7 @@ protected:
 
 public:
 	enum {
+		// Keep in sync with CanvasItem and Node3D.
 		NOTIFICATION_TRANSFORM_CHANGED = 2000
 	};
 
diff --git a/scene/resources/packed_scene.h b/scene/resources/packed_scene.h
index 74ebbd8b61..f95b4bf313 100644
--- a/scene/resources/packed_scene.h
+++ b/scene/resources/packed_scene.h
@@ -33,6 +33,8 @@
 #include "core/io/resource.h"
 #include "scene/main/node.h"
 
+class PackedScene;
+
 class SceneState : public RefCounted {
 	GDCLASS(SceneState, RefCounted);
 
diff --git a/scene/scene_string_names.h b/scene/scene_string_names.h
index 355e7889f0..b4827345a6 100644
--- a/scene/scene_string_names.h
+++ b/scene/scene_string_names.h
@@ -30,7 +30,6 @@
 
 #pragma once
 
-#include "core/string/node_path.h"
 #include "core/string/string_name.h"
 
 class SceneStringNames {
@@ -126,8 +125,6 @@ public:
 	const StringName blend_times = "blend_times";
 	const StringName speed = "speed";
 
-	const NodePath path_pp = NodePath("..");
-
 	const StringName default_ = "default"; // default would conflict with C++ keyword.
 	const StringName output = "output";
 
diff --git a/scene/theme/theme_db.cpp b/scene/theme/theme_db.cpp
index 792acfd57a..931f324991 100644
--- a/scene/theme/theme_db.cpp
+++ b/scene/theme/theme_db.cpp
@@ -35,6 +35,7 @@
 #include "core/io/resource_loader.h"
 #include "core/object/callable_mp.h"
 #include "core/object/class_db.h"
+#include "core/object/message_queue.h"
 #include "scene/gui/control.h"
 #include "scene/main/node.h"
 #include "scene/main/window.h"