diff --git a/Core/GDCore/Events/EventsList.cpp b/Core/GDCore/Events/EventsList.cpp
index b2c9361588ce..36c1d493cc27 100644
--- a/Core/GDCore/Events/EventsList.cpp
+++ b/Core/GDCore/Events/EventsList.cpp
@@ -53,7 +53,7 @@ void EventsList::InsertEvent(std::shared_ptr<gd::BaseEvent> event,
     events.push_back(event);
 }
 
-gd::BaseEvent& EventsList::InsertNewEvent(gd::Project& project,
+gd::BaseEvent& EventsList::InsertNewEvent(const gd::Project& project,
                                           const gd::String& eventType,
                                           size_t position) {
   gd::BaseEventSPtr event = project.CreateEvent(eventType);
diff --git a/Core/GDCore/Events/EventsList.h b/Core/GDCore/Events/EventsList.h
index ecb81b76a849..e98e0f54003a 100644
--- a/Core/GDCore/Events/EventsList.h
+++ b/Core/GDCore/Events/EventsList.h
@@ -66,7 +66,7 @@ class GD_CORE_API EventsList {
    * \param position Insertion position. If the position is invalid, the object
    * is inserted at the end of the objects list.
    */
-  gd::BaseEvent& InsertNewEvent(gd::Project& project,
+  gd::BaseEvent& InsertNewEvent(const gd::Project& project,
                                 const gd::String& eventType,
                                 size_t position = (size_t)-1);
 
diff --git a/Core/GDCore/IDE/ExtensionEditor/ChildObjectForwardFunctionGenerator.cpp b/Core/GDCore/IDE/ExtensionEditor/ChildObjectForwardFunctionGenerator.cpp
new file mode 100644
index 000000000000..4b045fe50096
--- /dev/null
+++ b/Core/GDCore/IDE/ExtensionEditor/ChildObjectForwardFunctionGenerator.cpp
@@ -0,0 +1,248 @@
+/*
+ * GDevelop Core
+ * Copyright 2008-present Florian Rival (Florian.Rival@gmail.com). All rights
+ * reserved. This project is released under the MIT License.
+ */
+#include "ChildObjectForwardFunctionGenerator.h"
+
+#include "GDCore/Events/Builtin/CommentEvent.h"
+#include "GDCore/Events/Builtin/StandardEvent.h"
+#include "GDCore/Extensions/Metadata/BehaviorMetadata.h"
+#include "GDCore/Extensions/Metadata/MetadataProvider.h"
+#include "GDCore/Extensions/PlatformExtension.h"
+#include "GDCore/IDE/WholeProjectRefactorer.h"
+#include "GDCore/Project/EventsBasedObject.h"
+#include "GDCore/Project/EventsFunction.h"
+#include "GDCore/Project/EventsFunctionsExtension.h"
+#include "GDCore/Project/Object.h"
+#include "GDCore/Project/Project.h"
+#include "GDCore/String.h"
+
+namespace gd {
+
+void ChildObjectForwardFunctionGenerator::GenerateChildObjectForwardFunctions(
+    const gd::Project &project,
+    const gd::EventsFunctionsExtension &eventsFunctionsExtension,
+    gd::EventsBasedObject &eventsBasedObject,
+    const gd::String &childObjectName) {
+  if (!eventsBasedObject.GetObjects().HasObjectNamed(childObjectName)) {
+    return;
+  }
+  auto &childObject = eventsBasedObject.GetObjects().GetObject(childObjectName);
+  if (!project.HasEventsBasedObject(childObject.GetType())) {
+    return;
+  }
+  auto &childEventsBasedObject =
+      project.GetEventsBasedObject(childObject.GetType());
+  for (auto &childEventsFunction :
+       childEventsBasedObject.GetEventsFunctions().GetInternalVector()) {
+    if (childEventsFunction->IsPrivate() ||
+        childEventsFunction->IsDeprecated() ||
+        gd::EventsBasedObject::IsObjectLifecycleEventsFunction(
+            childEventsFunction->GetName())) {
+      continue;
+    }
+    ChildObjectForwardFunctionGenerator::GenerateChildObjectForwardFunction(
+        project, eventsFunctionsExtension, eventsBasedObject, childObjectName,
+        *childEventsFunction);
+  }
+}
+
+void ChildObjectForwardFunctionGenerator::GenerateChildObjectForwardFunction(
+    const gd::Project &project,
+    const gd::EventsFunctionsExtension &parentEventsFunctionsExtension,
+    gd::EventsBasedObject &parentEventsBasedObject,
+    const gd::String &childObjectName,
+    const gd::EventsFunction &childEventsFunction) {
+  if (!parentEventsBasedObject.GetObjects().HasObjectNamed(childObjectName)) {
+    return;
+  }
+  auto &childObject =
+      parentEventsBasedObject.GetObjects().GetObject(childObjectName);
+  if (!project.HasEventsBasedObject(childObject.GetType())) {
+    return;
+  }
+  auto &childEventsBasedObject =
+      project.GetEventsBasedObject(childObject.GetType());
+  auto &functionName = childEventsFunction.GetName();
+  if (parentEventsBasedObject.GetEventsFunctions().HasEventsFunctionNamed(
+          functionName)) {
+    return;
+  }
+  auto &parentEventsFunction =
+      parentEventsBasedObject.GetEventsFunctions().InsertEventsFunction(
+          childEventsFunction, 0);
+  parentEventsFunction.GetEvents().Clear();
+  parentEventsBasedObject.GetEventsFunctions()
+      .AddMissingFunctionsInRootFolder();
+  auto &rootFolder =
+      parentEventsBasedObject.GetEventsFunctions().GetRootFolder();
+  // TODO Handle sub-folders
+  auto &folder =
+      !childEventsFunction.GetGroup().empty()
+          ? rootFolder.GetOrCreateChildFolder(childEventsFunction.GetGroup())
+          : rootFolder;
+  rootFolder.MoveFunctionFolderOrFunctionToAnotherFolder(
+      rootFolder.GetFunctionNamed(parentEventsFunction.GetName()), folder,
+      folder.GetChildrenCount());
+  gd::WholeProjectRefactorer::EnsureObjectEventsFunctionsProperParameters(
+      parentEventsFunctionsExtension, parentEventsBasedObject);
+
+  auto childExtensionName =
+      gd::PlatformExtension::GetExtensionFromFullObjectType(
+          childObject.GetType());
+  auto childFunctionType =
+      gd::PlatformExtension::GetObjectEventsFunctionFullType(
+          childExtensionName, childEventsBasedObject.GetName(), functionName);
+
+  bool hasAnyBooleanParameter = false;
+  for (auto &parameter :
+       parentEventsFunction.GetParameters().GetInternalVector()) {
+    if (parameter->GetValueTypeMetadata().IsBoolean()) {
+      hasAnyBooleanParameter = true;
+      break;
+    }
+  }
+  if (hasAnyBooleanParameter &&
+      parentEventsFunction.GetParameters().GetParametersCount() > 2) {
+    auto &event = dynamic_cast<gd::CommentEvent &>(
+        parentEventsFunction.GetEvents().InsertNewEvent(
+            project, "BuiltinCommonInstructions::Comment", 0));
+    event.SetComment("TODO: Please implement this function manually.");
+    return;
+  }
+  auto &event = dynamic_cast<gd::StandardEvent &>(
+      parentEventsFunction.GetEvents().InsertNewEvent(
+          project, "BuiltinCommonInstructions::Standard", 0));
+  switch (childEventsFunction.GetFunctionType()) {
+  case gd::EventsFunction::FunctionType::ActionWithOperator:
+  case gd::EventsFunction::FunctionType::Action: {
+    if (parentEventsFunction.GetParameters().GetParametersCount() == 2 &&
+        hasAnyBooleanParameter) {
+      gd::Instruction condition;
+      condition.SetType("BooleanVariable");
+      condition.AddParameter("Value");
+      condition.AddParameter("True");
+      condition.AddParameter("");
+      event.GetConditions().Insert(condition, 0);
+
+      gd::Instruction action;
+      action.SetType(childFunctionType);
+      action.AddParameter(childObjectName);
+      action.AddParameter("yes");
+      event.GetActions().Insert(action, 0);
+      {
+        auto &event = dynamic_cast<gd::StandardEvent &>(
+            parentEventsFunction.GetEvents().InsertNewEvent(
+                project, "BuiltinCommonInstructions::Standard", 0));
+
+        gd::Instruction condition;
+        condition.SetType("BooleanVariable");
+        condition.AddParameter("Value");
+        condition.AddParameter("False");
+        condition.AddParameter("");
+        event.GetConditions().Insert(condition, 0);
+
+        gd::Instruction action;
+        action.SetType(childFunctionType);
+        action.AddParameter(childObjectName);
+        action.AddParameter("no");
+        event.GetActions().Insert(action, 0);
+      }
+    } else {
+      gd::Instruction action;
+      action.SetType(childFunctionType);
+      for (auto &parameter :
+           childEventsFunction
+               .GetParametersForEvents(
+                   parentEventsBasedObject.GetEventsFunctions())
+               .GetInternalVector()) {
+        if (childEventsFunction.GetFunctionType() ==
+                gd::EventsFunction::FunctionType::ActionWithOperator &&
+            parameter->GetName() == "Value") {
+          action.AddParameter("=");
+        }
+        action.AddParameter(parameter->GetName());
+      }
+      action.SetParameter(0, childObjectName);
+      event.GetActions().Insert(action, 0);
+      if (childEventsFunction.IsAsync()) {
+        gd::Instruction action;
+        action.SetType("BuiltinAsync::ResolveAsyncEventsFunction");
+        event.GetActions().Insert(action, 1);
+      }
+    }
+    break;
+  }
+  case gd::EventsFunction::FunctionType::Condition: {
+    gd::Instruction condition;
+    condition.SetType(childFunctionType);
+    for (auto &parameter : childEventsFunction
+                               .GetParametersForEvents(
+                                   parentEventsBasedObject.GetEventsFunctions())
+                               .GetInternalVector()) {
+      condition.AddParameter(parameter->GetName());
+    }
+    condition.SetParameter(0, childObjectName);
+    event.GetConditions().Insert(condition, 0);
+
+    gd::Instruction action;
+    action.SetType("SetReturnBoolean");
+    action.AddParameter("True");
+    event.GetActions().Insert(action, 0);
+    if (childEventsFunction.IsAsync()) {
+      gd::Instruction action;
+      action.SetType("BuiltinAsync::ResolveAsyncEventsFunction");
+      event.GetActions().Insert(action, 1);
+    }
+    break;
+  }
+  case gd::EventsFunction::FunctionType::ExpressionAndCondition:
+  case gd::EventsFunction::FunctionType::Expression: {
+    gd::Instruction action;
+    action.SetType(childEventsFunction.GetExpressionType().IsNumber()
+                       ? "SetReturnNumber"
+                       : "SetReturnString");
+    gd::String expression =
+        childObjectName + "." + childEventsFunction.GetName() + "(";
+    auto &parameters = childEventsFunction.GetParametersForEvents(
+        parentEventsBasedObject.GetEventsFunctions());
+    for (size_t i = 1; i < parameters.GetParametersCount(); i++) {
+      if (i > 1) {
+        expression += ", ";
+      }
+      expression += parameters.GetParameter(i).GetName();
+    }
+    expression += ")";
+    action.AddParameter(expression);
+    event.GetActions().Insert(action, 0);
+    break;
+  }
+  default:
+    break;
+  }
+}
+
+bool ChildObjectForwardFunctionGenerator::HasAnyChildCustomObject(
+    const gd::Project &project, gd::EventsBasedObject &eventsBasedObject) {
+  for (auto &childObject : eventsBasedObject.GetObjects().GetObjects()) {
+    if (project.HasEventsBasedObject(childObject->GetType())) {
+      return true;
+    }
+  }
+  return false;
+}
+
+std::vector<gd::String>
+ChildObjectForwardFunctionGenerator::GetChildCustomObjectNames(
+    const gd::Project &project, gd::EventsBasedObject &eventsBasedObject) {
+  std::vector<gd::String> objectNames;
+  for (auto &childObject : eventsBasedObject.GetObjects().GetObjects()) {
+    if (project.HasEventsBasedObject(childObject->GetType())) {
+      objectNames.push_back(childObject->GetName());
+    }
+  }
+  return objectNames;
+}
+
+} // namespace gd
diff --git a/Core/GDCore/IDE/ExtensionEditor/ChildObjectForwardFunctionGenerator.h b/Core/GDCore/IDE/ExtensionEditor/ChildObjectForwardFunctionGenerator.h
new file mode 100644
index 000000000000..2509f543998a
--- /dev/null
+++ b/Core/GDCore/IDE/ExtensionEditor/ChildObjectForwardFunctionGenerator.h
@@ -0,0 +1,47 @@
+/*
+ * GDevelop Core
+ * Copyright 2008-present Florian Rival (Florian.Rival@gmail.com). All rights
+ * reserved. This project is released under the MIT License.
+ */
+#pragma once
+
+#include "GDCore/String.h"
+#include <vector>
+
+namespace gd {
+class Project;
+class EventsFunctionsExtension;
+class EventsBasedObject;
+class EventsFunction;
+class Object;
+} // namespace gd
+
+namespace gd {
+/**
+ * Generate events functions in a custom object that forwards the call to one of
+ * its child object. It allows users to quickly expose features from a child
+ * object.
+ */
+class GD_CORE_API ChildObjectForwardFunctionGenerator {
+public:
+  static void GenerateChildObjectForwardFunctions(
+      const gd::Project &project,
+      const gd::EventsFunctionsExtension &parentEventsFunctionsExtension,
+      gd::EventsBasedObject &parentEventsBasedObject,
+      const gd::String &childObjectName);
+
+  static void GenerateChildObjectForwardFunction(
+      const gd::Project &project,
+      const gd::EventsFunctionsExtension &parentEventsFunctionsExtension,
+      gd::EventsBasedObject &parentEventsBasedObject,
+      const gd::String &childObjectName,
+      const gd::EventsFunction &eventsFunction);
+
+  static bool HasAnyChildCustomObject(const gd::Project &project,
+                                      gd::EventsBasedObject &eventsBasedObject);
+
+  static std::vector<gd::String>
+  GetChildCustomObjectNames(const gd::Project &project,
+                            gd::EventsBasedObject &eventsBasedObject);
+};
+} // namespace gd
diff --git a/Core/GDCore/IDE/EventsFunctionsExtensionExtractor.cpp b/Core/GDCore/IDE/ExtensionEditor/EventsFunctionsExtensionExtractor.cpp
similarity index 100%
rename from Core/GDCore/IDE/EventsFunctionsExtensionExtractor.cpp
rename to Core/GDCore/IDE/ExtensionEditor/EventsFunctionsExtensionExtractor.cpp
diff --git a/Core/GDCore/IDE/EventsFunctionsExtensionExtractor.h b/Core/GDCore/IDE/ExtensionEditor/EventsFunctionsExtensionExtractor.h
similarity index 100%
rename from Core/GDCore/IDE/EventsFunctionsExtensionExtractor.h
rename to Core/GDCore/IDE/ExtensionEditor/EventsFunctionsExtensionExtractor.h
diff --git a/Core/GDCore/IDE/PropertyFunctionGenerator.cpp b/Core/GDCore/IDE/ExtensionEditor/PropertyFunctionGenerator.cpp
similarity index 100%
rename from Core/GDCore/IDE/PropertyFunctionGenerator.cpp
rename to Core/GDCore/IDE/ExtensionEditor/PropertyFunctionGenerator.cpp
diff --git a/Core/GDCore/IDE/PropertyFunctionGenerator.h b/Core/GDCore/IDE/ExtensionEditor/PropertyFunctionGenerator.h
similarity index 100%
rename from Core/GDCore/IDE/PropertyFunctionGenerator.h
rename to Core/GDCore/IDE/ExtensionEditor/PropertyFunctionGenerator.h
diff --git a/Core/GDCore/Project/EventsBasedObject.cpp b/Core/GDCore/Project/EventsBasedObject.cpp
index a1780820fdf4..e3fe875b9fad 100644
--- a/Core/GDCore/Project/EventsBasedObject.cpp
+++ b/Core/GDCore/Project/EventsBasedObject.cpp
@@ -88,4 +88,10 @@ void EventsBasedObject::UnserializeDefaultVariantFrom(
   defaultVariant.SetName("");
 }
 
+bool EventsBasedObject::IsObjectLifecycleEventsFunction(
+    const gd::String &functionName) {
+  return functionName == "onCreated" || functionName == "doStepPostEvents" ||
+         functionName == "onDestroy" || functionName == "onHotReloading";
+}
+
 }  // namespace gd
diff --git a/Core/GDCore/Project/EventsBasedObject.h b/Core/GDCore/Project/EventsBasedObject.h
index 60d6b988895e..07ecad05dcc9 100644
--- a/Core/GDCore/Project/EventsBasedObject.h
+++ b/Core/GDCore/Project/EventsBasedObject.h
@@ -391,7 +391,19 @@ class GD_CORE_API EventsBasedObject: public AbstractEventsBasedEntity {
   void UnserializeDefaultVariantFrom(gd::Project &project,
                                      const SerializerElement &element);
 
- private:
+  /** \name Lifecycle event functions
+   */
+  ///@{
+  /**
+   * Check if the name of the function is the name of a lifecycle function (for
+   * events-based objects), that will be called automatically by the game
+   * engine.
+   */
+  static bool
+  IsObjectLifecycleEventsFunction(const gd::String &eventsFunctionName);
+  ///@}
+
+private:
   gd::String defaultName;
   gd::String assetStoreTag;
   bool isRenderedIn3D;
diff --git a/Core/GDCore/Project/EventsFunctionsContainer.cpp b/Core/GDCore/Project/EventsFunctionsContainer.cpp
index 4b233b28ce1b..ca2ef4acf6a6 100644
--- a/Core/GDCore/Project/EventsFunctionsContainer.cpp
+++ b/Core/GDCore/Project/EventsFunctionsContainer.cpp
@@ -58,6 +58,7 @@ void EventsFunctionsContainer::AddMissingFunctionsInRootFolder() {
         }
       }
       const gd::String &group = groupSource->GetGroup();
+      // TODO Handle sub-folders
       auto &folder = !group.empty() ? rootFolder->GetOrCreateChildFolder(group)
                                     : *rootFolder;
       folder.InsertFunction(&function);
diff --git a/Core/GDCore/Project/Project.cpp b/Core/GDCore/Project/Project.cpp
index 0f673aa228d6..db176268b6be 100644
--- a/Core/GDCore/Project/Project.cpp
+++ b/Core/GDCore/Project/Project.cpp
@@ -231,7 +231,7 @@ const gd::EventsBasedBehavior& Project::GetEventsBasedBehavior(
 }
 
 std::shared_ptr<gd::BaseEvent> Project::CreateEvent(
-    const gd::String& type, const gd::String& platformName) {
+    const gd::String& type, const gd::String& platformName) const {
   for (std::size_t i = 0; i < platforms.size(); ++i) {
     if (!platformName.empty() && platforms[i]->GetName() != platformName)
       continue;
diff --git a/Core/GDCore/Project/Project.h b/Core/GDCore/Project/Project.h
index febc6d7c573b..0f1da1f343e5 100644
--- a/Core/GDCore/Project/Project.h
+++ b/Core/GDCore/Project/Project.h
@@ -569,7 +569,7 @@ class GD_CORE_API Project {
    * first platform supporting the object is used.
    */
   std::shared_ptr<gd::BaseEvent> CreateEvent(
-      const gd::String& type, const gd::String& platformName = "");
+      const gd::String& type, const gd::String& platformName = "") const;
   ///@}
 
   /** \name Layouts management
diff --git a/Core/tests/ChildObjectForwardFunctionGenerator.cpp b/Core/tests/ChildObjectForwardFunctionGenerator.cpp
new file mode 100644
index 000000000000..e39aeb9e4750
--- /dev/null
+++ b/Core/tests/ChildObjectForwardFunctionGenerator.cpp
@@ -0,0 +1,527 @@
+/*
+ * GDevelop Core
+ * Copyright 2008-2016 Florian Rival (Florian.Rival@gmail.com). All rights
+ * reserved. This project is released under the MIT License.
+ */
+/**
+ * @file Tests covering common features of GDevelop Core.
+ */
+#include "GDCore/IDE/ExtensionEditor/ChildObjectForwardFunctionGenerator.h"
+#include "DummyPlatform.h"
+#include "GDCore/Events/Builtin/CommentEvent.h"
+#include "GDCore/Events/Builtin/StandardEvent.h"
+#include "GDCore/Extensions/Metadata/ValueTypeMetadata.h"
+#include "GDCore/Extensions/Platform.h"
+#include "GDCore/IDE/WholeProjectRefactorer.h"
+#include "GDCore/Project/EventsBasedBehavior.h"
+#include "GDCore/Project/EventsFunctionsExtension.h"
+#include "GDCore/Project/Project.h"
+#include "GDCore/String.h"
+#include "catch.hpp"
+
+TEST_CASE("ChildObjectForwardFunctionGenerator", "[common]") {
+  SECTION("Can generate a function to forward an action") {
+    gd::Platform platform;
+    gd::Project project;
+    SetupProjectWithDummyPlatform(project, platform);
+    auto &extension =
+        project.InsertNewEventsFunctionsExtension("MyEventsExtension", 0);
+    auto &parentEventsBasedObject = extension.GetEventsBasedObjects().InsertNew(
+        "MyParentEventsBasedObject", 0);
+    auto &childEventsBasedObject = extension.GetEventsBasedObjects().InsertNew(
+        "MyChildEventsBasedObject", 0);
+    parentEventsBasedObject.GetObjects().InsertNewObject(
+        project, "MyEventsExtension::MyChildEventsBasedObject", "MyChildObject",
+        0);
+
+    auto &childFunction =
+        childEventsBasedObject.GetEventsFunctions().InsertNewEventsFunction(
+            "MyFunction", 0);
+    childFunction.SetFunctionType(gd::EventsFunction::FunctionType::Action);
+    childFunction.SetFullName("My function");
+    gd::WholeProjectRefactorer::EnsureObjectEventsFunctionsProperParameters(
+        extension, childEventsBasedObject);
+    {
+      auto &parameter =
+          childFunction.GetParameters().AddNewParameter("MyStringParameter");
+      parameter.SetType("string");
+    }
+    {
+      auto &parameter =
+          childFunction.GetParameters().AddNewParameter("MyNumberParameter");
+      parameter.SetType("number");
+    }
+
+    gd::ChildObjectForwardFunctionGenerator::
+        GenerateChildObjectForwardFunctions(
+            project, extension, parentEventsBasedObject, "MyChildObject");
+
+    REQUIRE(parentEventsBasedObject.GetEventsFunctions().HasEventsFunctionNamed(
+        "MyFunction"));
+    auto &parentFunction =
+        parentEventsBasedObject.GetEventsFunctions().GetEventsFunction(
+            "MyFunction");
+
+    REQUIRE(parentFunction.GetFullName() == "My function");
+    REQUIRE(parentFunction.GetParameters().GetParametersCount() == 3);
+    REQUIRE(parentFunction.GetParameters().GetParameter(0).GetType() ==
+            "object");
+    REQUIRE(parentFunction.GetParameters().GetParameter(0).GetExtraInfo() ==
+            "MyEventsExtension::MyParentEventsBasedObject");
+    REQUIRE(parentFunction.GetParameters().GetParameter(1).GetType() ==
+            "string");
+    REQUIRE(parentFunction.GetParameters().GetParameter(2).GetType() ==
+            "number");
+
+    REQUIRE(parentFunction.GetEvents().GetEventsCount() == 1);
+    auto &event = parentFunction.GetEvents().GetEvent(0);
+    REQUIRE(event.GetInstructionList("conditions")->GetCount() == 0);
+    REQUIRE(event.GetInstructionList("actions")->GetCount() == 1);
+    auto &action = event.GetInstructionList("actions")->Get(0);
+    REQUIRE(action.GetType() ==
+            "MyEventsExtension::MyChildEventsBasedObject::MyFunction");
+    REQUIRE(action.GetParametersCount() == 3);
+    REQUIRE(action.GetParameter(0).GetPlainString() == "MyChildObject");
+    REQUIRE(action.GetParameter(1).GetPlainString() == "MyStringParameter");
+    REQUIRE(action.GetParameter(2).GetPlainString() == "MyNumberParameter");
+  }
+
+  SECTION("Can generate a function to forward a condition") {
+    gd::Platform platform;
+    gd::Project project;
+    SetupProjectWithDummyPlatform(project, platform);
+    auto &extension =
+        project.InsertNewEventsFunctionsExtension("MyEventsExtension", 0);
+    auto &parentEventsBasedObject = extension.GetEventsBasedObjects().InsertNew(
+        "MyParentEventsBasedObject", 0);
+    auto &childEventsBasedObject = extension.GetEventsBasedObjects().InsertNew(
+        "MyChildEventsBasedObject", 0);
+
+    parentEventsBasedObject.GetObjects().InsertNewObject(
+        project, "MyEventsExtension::MyChildEventsBasedObject", "MyChildObject",
+        0);
+    auto &childFunction =
+        childEventsBasedObject.GetEventsFunctions().InsertNewEventsFunction(
+            "MyFunction", 0);
+    childFunction.SetFunctionType(gd::EventsFunction::FunctionType::Condition);
+    childFunction.SetFullName("My function");
+    gd::WholeProjectRefactorer::EnsureObjectEventsFunctionsProperParameters(
+        extension, childEventsBasedObject);
+    {
+      auto &parameter =
+          childFunction.GetParameters().AddNewParameter("MyStringParameter");
+      parameter.SetType("string");
+    }
+    {
+      auto &parameter =
+          childFunction.GetParameters().AddNewParameter("MyNumberParameter");
+      parameter.SetType("number");
+    }
+
+    gd::ChildObjectForwardFunctionGenerator::
+        GenerateChildObjectForwardFunctions(
+            project, extension, parentEventsBasedObject, "MyChildObject");
+
+    REQUIRE(parentEventsBasedObject.GetEventsFunctions().HasEventsFunctionNamed(
+        "MyFunction"));
+    auto &parentFunction =
+        parentEventsBasedObject.GetEventsFunctions().GetEventsFunction(
+            "MyFunction");
+
+    REQUIRE(parentFunction.GetFullName() == "My function");
+    REQUIRE(parentFunction.GetParameters().GetParametersCount() == 3);
+    REQUIRE(parentFunction.GetParameters().GetParameter(0).GetType() ==
+            "object");
+    REQUIRE(parentFunction.GetParameters().GetParameter(0).GetExtraInfo() ==
+            "MyEventsExtension::MyParentEventsBasedObject");
+    REQUIRE(parentFunction.GetParameters().GetParameter(1).GetType() ==
+            "string");
+    REQUIRE(parentFunction.GetParameters().GetParameter(2).GetType() ==
+            "number");
+
+    REQUIRE(parentFunction.GetEvents().GetEventsCount() == 1);
+    auto &event = parentFunction.GetEvents().GetEvent(0);
+    REQUIRE(event.GetInstructionList("conditions")->GetCount() == 1);
+    auto &condition = event.GetInstructionList("conditions")->Get(0);
+    REQUIRE(condition.GetType() ==
+            "MyEventsExtension::MyChildEventsBasedObject::MyFunction");
+    REQUIRE(condition.GetParametersCount() == 3);
+    REQUIRE(condition.GetParameter(0).GetPlainString() == "MyChildObject");
+    REQUIRE(condition.GetParameter(1).GetPlainString() == "MyStringParameter");
+    REQUIRE(condition.GetParameter(2).GetPlainString() == "MyNumberParameter");
+
+    REQUIRE(event.GetInstructionList("actions")->GetCount() == 1);
+    auto &action = event.GetInstructionList("actions")->Get(0);
+    REQUIRE(action.GetType() == "SetReturnBoolean");
+    REQUIRE(action.GetParametersCount() == 1);
+    REQUIRE(action.GetParameter(0).GetPlainString() == "True");
+  }
+
+  SECTION("Can generate a function to forward an expression") {
+    gd::Platform platform;
+    gd::Project project;
+    SetupProjectWithDummyPlatform(project, platform);
+    auto &extension =
+        project.InsertNewEventsFunctionsExtension("MyEventsExtension", 0);
+    auto &parentEventsBasedObject = extension.GetEventsBasedObjects().InsertNew(
+        "MyParentEventsBasedObject", 0);
+    auto &childEventsBasedObject = extension.GetEventsBasedObjects().InsertNew(
+        "MyChildEventsBasedObject", 0);
+
+    parentEventsBasedObject.GetObjects().InsertNewObject(
+        project, "MyEventsExtension::MyChildEventsBasedObject", "MyChildObject",
+        0);
+    auto &childFunction =
+        childEventsBasedObject.GetEventsFunctions().InsertNewEventsFunction(
+            "MyFunction", 0);
+    childFunction.SetFunctionType(gd::EventsFunction::FunctionType::Expression);
+    childFunction.SetFullName("My function");
+    gd::WholeProjectRefactorer::EnsureObjectEventsFunctionsProperParameters(
+        extension, childEventsBasedObject);
+    {
+      auto &parameter =
+          childFunction.GetParameters().AddNewParameter("MyStringParameter");
+      parameter.SetType("string");
+    }
+    {
+      auto &parameter =
+          childFunction.GetParameters().AddNewParameter("MyNumberParameter");
+      parameter.SetType("number");
+    }
+
+    gd::ChildObjectForwardFunctionGenerator::
+        GenerateChildObjectForwardFunctions(
+            project, extension, parentEventsBasedObject, "MyChildObject");
+
+    REQUIRE(parentEventsBasedObject.GetEventsFunctions().HasEventsFunctionNamed(
+        "MyFunction"));
+    auto &parentFunction =
+        parentEventsBasedObject.GetEventsFunctions().GetEventsFunction(
+            "MyFunction");
+
+    REQUIRE(parentFunction.GetFullName() == "My function");
+    REQUIRE(parentFunction.GetFunctionType() ==
+            gd::EventsFunction::FunctionType::Expression);
+    REQUIRE(parentFunction.GetExpressionType().IsNumber());
+    REQUIRE(parentFunction.GetParameters().GetParametersCount() == 3);
+    REQUIRE(parentFunction.GetParameters().GetParameter(0).GetType() ==
+            "object");
+    REQUIRE(parentFunction.GetParameters().GetParameter(0).GetExtraInfo() ==
+            "MyEventsExtension::MyParentEventsBasedObject");
+    REQUIRE(parentFunction.GetParameters().GetParameter(1).GetType() ==
+            "string");
+    REQUIRE(parentFunction.GetParameters().GetParameter(2).GetType() ==
+            "number");
+
+    REQUIRE(parentFunction.GetEvents().GetEventsCount() == 1);
+    auto &event = parentFunction.GetEvents().GetEvent(0);
+    REQUIRE(event.GetInstructionList("conditions")->GetCount() == 0);
+    REQUIRE(event.GetInstructionList("actions")->GetCount() == 1);
+    auto &action = event.GetInstructionList("actions")->Get(0);
+    REQUIRE(action.GetType() == "SetReturnNumber");
+    REQUIRE(action.GetParametersCount() == 1);
+    REQUIRE(action.GetParameter(0).GetPlainString() ==
+            "MyChildObject.MyFunction(MyStringParameter, MyNumberParameter)");
+  }
+
+  SECTION("Can generate a function to forward a getter and setter") {
+    gd::Platform platform;
+    gd::Project project;
+    SetupProjectWithDummyPlatform(project, platform);
+    auto &extension =
+        project.InsertNewEventsFunctionsExtension("MyEventsExtension", 0);
+    auto &parentEventsBasedObject = extension.GetEventsBasedObjects().InsertNew(
+        "MyParentEventsBasedObject", 0);
+    auto &childEventsBasedObject = extension.GetEventsBasedObjects().InsertNew(
+        "MyChildEventsBasedObject", 0);
+
+    parentEventsBasedObject.GetObjects().InsertNewObject(
+        project, "MyEventsExtension::MyChildEventsBasedObject", "MyChildObject",
+        0);
+    {
+      auto &childFunction =
+          childEventsBasedObject.GetEventsFunctions().InsertNewEventsFunction(
+              "MyGetterFunction", 0);
+      childFunction.SetFunctionType(
+          gd::EventsFunction::FunctionType::ExpressionAndCondition);
+      childFunction.GetExpressionType().SetName("number");
+      gd::WholeProjectRefactorer::EnsureObjectEventsFunctionsProperParameters(
+          extension, childEventsBasedObject);
+    }
+    {
+      auto &childFunction =
+          childEventsBasedObject.GetEventsFunctions().InsertNewEventsFunction(
+              "MySetterFunction", 1);
+      childFunction.SetFunctionType(
+          gd::EventsFunction::FunctionType::ActionWithOperator);
+      childFunction.SetGetterName("MyGetterFunction");
+      gd::WholeProjectRefactorer::EnsureObjectEventsFunctionsProperParameters(
+          extension, childEventsBasedObject);
+    }
+
+    gd::ChildObjectForwardFunctionGenerator::
+        GenerateChildObjectForwardFunctions(
+            project, extension, parentEventsBasedObject, "MyChildObject");
+
+    {
+      REQUIRE(
+          parentEventsBasedObject.GetEventsFunctions().HasEventsFunctionNamed(
+              "MyGetterFunction"));
+      auto &parentFunction =
+          parentEventsBasedObject.GetEventsFunctions().GetEventsFunction(
+              "MyGetterFunction");
+      REQUIRE(parentFunction.GetFunctionType() ==
+              gd::EventsFunction::FunctionType::ExpressionAndCondition);
+      REQUIRE(parentFunction.GetExpressionType().IsNumber());
+      REQUIRE(parentFunction.GetParameters().GetParametersCount() == 1);
+      REQUIRE(parentFunction.GetParameters().GetParameter(0).GetType() ==
+              "object");
+      REQUIRE(parentFunction.GetParameters().GetParameter(0).GetExtraInfo() ==
+              "MyEventsExtension::MyParentEventsBasedObject");
+
+      REQUIRE(parentFunction.GetEvents().GetEventsCount() == 1);
+      auto &event = parentFunction.GetEvents().GetEvent(0);
+      REQUIRE(event.GetInstructionList("conditions")->GetCount() == 0);
+
+      REQUIRE(event.GetInstructionList("actions")->GetCount() == 1);
+      auto &action = event.GetInstructionList("actions")->Get(0);
+      REQUIRE(action.GetType() == "SetReturnNumber");
+      REQUIRE(action.GetParametersCount() == 1);
+      REQUIRE(action.GetParameter(0).GetPlainString() ==
+              "MyChildObject.MyGetterFunction()");
+    }
+    {
+      REQUIRE(
+          parentEventsBasedObject.GetEventsFunctions().HasEventsFunctionNamed(
+              "MySetterFunction"));
+      auto &parentFunction =
+          parentEventsBasedObject.GetEventsFunctions().GetEventsFunction(
+              "MySetterFunction");
+      REQUIRE(parentFunction.GetFunctionType() ==
+              gd::EventsFunction::FunctionType::ActionWithOperator);
+      REQUIRE(parentFunction.GetGetterName() == "MyGetterFunction");
+      REQUIRE(parentFunction.GetParameters().GetParametersCount() == 1);
+      REQUIRE(parentFunction.GetParameters().GetParameter(0).GetType() ==
+              "object");
+      REQUIRE(parentFunction.GetParameters().GetParameter(0).GetExtraInfo() ==
+              "MyEventsExtension::MyParentEventsBasedObject");
+
+      REQUIRE(parentFunction.GetEvents().GetEventsCount() == 1);
+      auto &event = parentFunction.GetEvents().GetEvent(0);
+      REQUIRE(event.GetInstructionList("conditions")->GetCount() == 0);
+
+      REQUIRE(event.GetInstructionList("actions")->GetCount() == 1);
+      auto &action = event.GetInstructionList("actions")->Get(0);
+      REQUIRE(action.GetType() ==
+              "MyEventsExtension::MyChildEventsBasedObject::MySetterFunction");
+      REQUIRE(action.GetParametersCount() == 3);
+      REQUIRE(action.GetParameter(0).GetPlainString() == "MyChildObject");
+      REQUIRE(action.GetParameter(1).GetPlainString() == "=");
+      REQUIRE(action.GetParameter(2).GetPlainString() == "Value");
+    }
+  }
+
+  SECTION("Can generate a function to forward a boolean setter") {
+    gd::Platform platform;
+    gd::Project project;
+    SetupProjectWithDummyPlatform(project, platform);
+    auto &extension =
+        project.InsertNewEventsFunctionsExtension("MyEventsExtension", 0);
+    auto &parentEventsBasedObject = extension.GetEventsBasedObjects().InsertNew(
+        "MyParentEventsBasedObject", 0);
+    auto &childEventsBasedObject = extension.GetEventsBasedObjects().InsertNew(
+        "MyChildEventsBasedObject", 0);
+
+    parentEventsBasedObject.GetObjects().InsertNewObject(
+        project, "MyEventsExtension::MyChildEventsBasedObject", "MyChildObject",
+        0);
+
+    auto &childFunction =
+        childEventsBasedObject.GetEventsFunctions().InsertNewEventsFunction(
+            "MySetterFunction", 1);
+    childFunction.SetFunctionType(gd::EventsFunction::FunctionType::Action);
+    gd::WholeProjectRefactorer::EnsureObjectEventsFunctionsProperParameters(
+        extension, childEventsBasedObject);
+    {
+      auto &parameter = childFunction.GetParameters().AddNewParameter("Value");
+      parameter.SetType("yesorno");
+    }
+
+    gd::ChildObjectForwardFunctionGenerator::
+        GenerateChildObjectForwardFunctions(
+            project, extension, parentEventsBasedObject, "MyChildObject");
+
+    REQUIRE(parentEventsBasedObject.GetEventsFunctions().HasEventsFunctionNamed(
+        "MySetterFunction"));
+    auto &parentFunction =
+        parentEventsBasedObject.GetEventsFunctions().GetEventsFunction(
+            "MySetterFunction");
+    REQUIRE(parentFunction.GetFunctionType() ==
+            gd::EventsFunction::FunctionType::Action);
+    REQUIRE(parentFunction.GetParameters().GetParametersCount() == 2);
+    REQUIRE(parentFunction.GetParameters().GetParameter(0).GetType() ==
+            "object");
+    REQUIRE(parentFunction.GetParameters().GetParameter(0).GetExtraInfo() ==
+            "MyEventsExtension::MyParentEventsBasedObject");
+    REQUIRE(parentFunction.GetParameters().GetParameter(1).GetType() ==
+            "yesorno");
+
+    REQUIRE(parentFunction.GetEvents().GetEventsCount() == 2);
+    {
+      auto &event = parentFunction.GetEvents().GetEvent(0);
+      REQUIRE(event.GetInstructionList("conditions")->GetCount() == 1);
+      auto &condition = event.GetInstructionList("conditions")->Get(0);
+      REQUIRE(condition.GetType() == "BooleanVariable");
+      REQUIRE(condition.GetParametersCount() == 3);
+      REQUIRE(condition.GetParameter(0).GetPlainString() == "Value");
+      REQUIRE(condition.GetParameter(1).GetPlainString() == "False");
+      REQUIRE(condition.GetParameter(2).GetPlainString() == "");
+
+      REQUIRE(event.GetInstructionList("actions")->GetCount() == 1);
+      auto &action = event.GetInstructionList("actions")->Get(0);
+      REQUIRE(action.GetType() ==
+              "MyEventsExtension::MyChildEventsBasedObject::MySetterFunction");
+      REQUIRE(action.GetParametersCount() == 2);
+      REQUIRE(action.GetParameter(0).GetPlainString() == "MyChildObject");
+      REQUIRE(action.GetParameter(1).GetPlainString() == "no");
+    }
+    {
+      auto &event = parentFunction.GetEvents().GetEvent(1);
+      REQUIRE(event.GetInstructionList("conditions")->GetCount() == 1);
+      auto &condition = event.GetInstructionList("conditions")->Get(0);
+      REQUIRE(condition.GetType() == "BooleanVariable");
+      REQUIRE(condition.GetParametersCount() == 3);
+      REQUIRE(condition.GetParameter(0).GetPlainString() == "Value");
+      REQUIRE(condition.GetParameter(1).GetPlainString() == "True");
+      REQUIRE(condition.GetParameter(2).GetPlainString() == "");
+
+      REQUIRE(event.GetInstructionList("actions")->GetCount() == 1);
+      auto &action = event.GetInstructionList("actions")->Get(0);
+      REQUIRE(action.GetType() ==
+              "MyEventsExtension::MyChildEventsBasedObject::MySetterFunction");
+      REQUIRE(action.GetParametersCount() == 2);
+      REQUIRE(action.GetParameter(0).GetPlainString() == "MyChildObject");
+      REQUIRE(action.GetParameter(1).GetPlainString() == "yes");
+    }
+  }
+
+  SECTION("Can generate a todo comment for function with boolean parameters") {
+    gd::Platform platform;
+    gd::Project project;
+    SetupProjectWithDummyPlatform(project, platform);
+    auto &extension =
+        project.InsertNewEventsFunctionsExtension("MyEventsExtension", 0);
+    auto &parentEventsBasedObject = extension.GetEventsBasedObjects().InsertNew(
+        "MyParentEventsBasedObject", 0);
+    auto &childEventsBasedObject = extension.GetEventsBasedObjects().InsertNew(
+        "MyChildEventsBasedObject", 0);
+
+    parentEventsBasedObject.GetObjects().InsertNewObject(
+        project, "MyEventsExtension::MyChildEventsBasedObject", "MyChildObject",
+        0);
+
+    auto &childFunction =
+        childEventsBasedObject.GetEventsFunctions().InsertNewEventsFunction(
+            "MySetterFunction", 1);
+    childFunction.SetFunctionType(gd::EventsFunction::FunctionType::Action);
+    gd::WholeProjectRefactorer::EnsureObjectEventsFunctionsProperParameters(
+        extension, childEventsBasedObject);
+    {
+      auto &parameter = childFunction.GetParameters().AddNewParameter("Value");
+      parameter.SetType("yesorno");
+    }
+    {
+      auto &parameter =
+          childFunction.GetParameters().AddNewParameter("MyNumberParameter");
+      parameter.SetType("number");
+    }
+
+    gd::ChildObjectForwardFunctionGenerator::
+        GenerateChildObjectForwardFunctions(
+            project, extension, parentEventsBasedObject, "MyChildObject");
+
+    REQUIRE(parentEventsBasedObject.GetEventsFunctions().HasEventsFunctionNamed(
+        "MySetterFunction"));
+    auto &parentFunction =
+        parentEventsBasedObject.GetEventsFunctions().GetEventsFunction(
+            "MySetterFunction");
+    REQUIRE(parentFunction.GetFunctionType() ==
+            gd::EventsFunction::FunctionType::Action);
+    REQUIRE(parentFunction.GetParameters().GetParametersCount() == 3);
+    REQUIRE(parentFunction.GetParameters().GetParameter(0).GetType() ==
+            "object");
+    REQUIRE(parentFunction.GetParameters().GetParameter(0).GetExtraInfo() ==
+            "MyEventsExtension::MyParentEventsBasedObject");
+    REQUIRE(parentFunction.GetParameters().GetParameter(1).GetType() ==
+            "yesorno");
+    REQUIRE(parentFunction.GetParameters().GetParameter(2).GetType() ==
+            "number");
+
+    REQUIRE(parentFunction.GetEvents().GetEventsCount() == 1);
+    {
+      auto &event = parentFunction.GetEvents().GetEvent(0);
+      REQUIRE(event.GetType() == "BuiltinCommonInstructions::Comment");
+      auto &comment = dynamic_cast<gd::CommentEvent &>(event);
+      REQUIRE(comment.GetComment() ==
+              "TODO: Please implement this function manually.");
+    }
+  }
+
+  SECTION("Can generate a function to forward an asynchronous action") {
+    gd::Platform platform;
+    gd::Project project;
+    SetupProjectWithDummyPlatform(project, platform);
+    auto &extension =
+        project.InsertNewEventsFunctionsExtension("MyEventsExtension", 0);
+    auto &parentEventsBasedObject = extension.GetEventsBasedObjects().InsertNew(
+        "MyParentEventsBasedObject", 0);
+    auto &childEventsBasedObject = extension.GetEventsBasedObjects().InsertNew(
+        "MyChildEventsBasedObject", 0);
+    parentEventsBasedObject.GetObjects().InsertNewObject(
+        project, "MyEventsExtension::MyChildEventsBasedObject", "MyChildObject",
+        0);
+
+    auto &childFunction =
+        childEventsBasedObject.GetEventsFunctions().InsertNewEventsFunction(
+            "MyFunction", 0);
+    childFunction.SetFunctionType(gd::EventsFunction::FunctionType::Action);
+    childFunction.SetAsync(true);
+    gd::WholeProjectRefactorer::EnsureObjectEventsFunctionsProperParameters(
+        extension, childEventsBasedObject);
+
+    gd::ChildObjectForwardFunctionGenerator::
+        GenerateChildObjectForwardFunctions(
+            project, extension, parentEventsBasedObject, "MyChildObject");
+
+    REQUIRE(parentEventsBasedObject.GetEventsFunctions().HasEventsFunctionNamed(
+        "MyFunction"));
+    auto &parentFunction =
+        parentEventsBasedObject.GetEventsFunctions().GetEventsFunction(
+            "MyFunction");
+    REQUIRE(parentFunction.GetFunctionType() ==
+            gd::EventsFunction::FunctionType::Action);
+    REQUIRE(parentFunction.IsAsync());
+    REQUIRE(parentFunction.GetParameters().GetParametersCount() == 1);
+    REQUIRE(parentFunction.GetParameters().GetParameter(0).GetType() ==
+            "object");
+    REQUIRE(parentFunction.GetParameters().GetParameter(0).GetExtraInfo() ==
+            "MyEventsExtension::MyParentEventsBasedObject");
+
+    REQUIRE(parentFunction.GetEvents().GetEventsCount() == 1);
+    auto &event = parentFunction.GetEvents().GetEvent(0);
+    REQUIRE(event.GetInstructionList("conditions")->GetCount() == 0);
+    REQUIRE(event.GetInstructionList("actions")->GetCount() == 2);
+    {
+      auto &action = event.GetInstructionList("actions")->Get(0);
+      REQUIRE(action.GetType() ==
+              "MyEventsExtension::MyChildEventsBasedObject::MyFunction");
+      REQUIRE(action.GetParametersCount() == 1);
+      REQUIRE(action.GetParameter(0).GetPlainString() == "MyChildObject");
+    }
+    {
+      auto &action = event.GetInstructionList("actions")->Get(1);
+      REQUIRE(action.GetType() == "BuiltinAsync::ResolveAsyncEventsFunction");
+      REQUIRE(action.GetParametersCount() == 0);
+    }
+  }
+}
diff --git a/Core/tests/DummyPlatform.cpp b/Core/tests/DummyPlatform.cpp
index 2f81fec23039..7fb42eced174 100644
--- a/Core/tests/DummyPlatform.cpp
+++ b/Core/tests/DummyPlatform.cpp
@@ -11,6 +11,7 @@
 #include "GDCore/Project/Layout.h"
 #include "GDCore/Project/Project.h"
 #include "GDCore/Tools/Localization.h"
+#include "GDCore/Events/Builtin/CommentEvent.h"
 #include "GDCore/Events/Builtin/StandardEvent.h"
 #include "GDCore/Events/Builtin/ForEachChildVariableEvent.h"
 #include "GDCore/Events/Builtin/RepeatEvent.h"
@@ -175,6 +176,7 @@ void SetupProjectWithDummyPlatform(gd::Project& project,
   commonInstructionsExtension->AddEvent("Else", "Else event", "", "", "", std::make_shared<gd::ElseEvent>());
   commonInstructionsExtension->AddEvent("ForEachChildVariable", "For each child variable event", "", "", "", std::make_shared<gd::ForEachChildVariableEvent>());
   commonInstructionsExtension->AddEvent("Repeat", "Repeat event", "", "", "", std::make_shared<gd::RepeatEvent>());
+  commonInstructionsExtension->AddEvent("Comment", "Comment event", "", "", "", std::make_shared<gd::CommentEvent>());
 
   std::shared_ptr<gd::PlatformExtension> baseObjectExtension =
       std::shared_ptr<gd::PlatformExtension>(new gd::PlatformExtension);
diff --git a/Core/tests/PropertyFunctionGenerator.cpp b/Core/tests/PropertyFunctionGenerator.cpp
index 076ac77e24da..ab4eadfb8153 100644
--- a/Core/tests/PropertyFunctionGenerator.cpp
+++ b/Core/tests/PropertyFunctionGenerator.cpp
@@ -6,7 +6,7 @@
 /**
  * @file Tests covering common features of GDevelop Core.
  */
-#include "GDCore/IDE/PropertyFunctionGenerator.h"
+#include "GDCore/IDE/ExtensionEditor/PropertyFunctionGenerator.h"
 #include "DummyPlatform.h"
 #include "GDCore/Events/Builtin/StandardEvent.h"
 #include "GDCore/Extensions/Metadata/ValueTypeMetadata.h"
diff --git a/GDJS/GDJS/Events/CodeGeneration/MetadataDeclarationHelper.cpp b/GDJS/GDJS/Events/CodeGeneration/MetadataDeclarationHelper.cpp
index e7397e40505f..3a601dc2a8d9 100644
--- a/GDJS/GDJS/Events/CodeGeneration/MetadataDeclarationHelper.cpp
+++ b/GDJS/GDJS/Events/CodeGeneration/MetadataDeclarationHelper.cpp
@@ -413,8 +413,7 @@ bool MetadataDeclarationHelper::IsBehaviorLifecycleEventsFunction(
  */
 bool MetadataDeclarationHelper::IsObjectLifecycleEventsFunction(
     const gd::String &functionName) {
-  return functionName == "onCreated" || functionName == "doStepPostEvents" ||
-         functionName == "onDestroy" || functionName == "onHotReloading";
+  return gd::EventsBasedObject::IsObjectLifecycleEventsFunction(functionName);
 }
 
 /**
diff --git a/GDevelop.js/Bindings/Bindings.idl b/GDevelop.js/Bindings/Bindings.idl
index d3f2e4bec026..2821aced0fce 100644
--- a/GDevelop.js/Bindings/Bindings.idl
+++ b/GDevelop.js/Bindings/Bindings.idl
@@ -3134,6 +3134,20 @@ interface PropertyFunctionGenerator {
 
 };
 
+interface ChildObjectForwardFunctionGenerator {
+    void STATIC_GenerateChildObjectForwardFunctions(
+        [Const, Ref] Project project,
+        [Const, Ref] EventsFunctionsExtension extension,
+        [Ref] EventsBasedObject eventsBasedObject,
+        [Const] DOMString childObjectName);
+    boolean STATIC_HasAnyChildCustomObject(
+        [Const, Ref] Project project,
+        [Ref] EventsBasedObject eventsBasedObject);
+    [Value] VectorString STATIC_GetChildCustomObjectNames(
+        [Const, Ref] Project project,
+        [Ref] EventsBasedObject eventsBasedObject);
+};
+
 interface UsedExtensionsResult {
   [Const, Ref] SetString GetUsedExtensions();
 };
diff --git a/GDevelop.js/Bindings/Wrapper.cpp b/GDevelop.js/Bindings/Wrapper.cpp
index 83ad7f3f65c3..7bcbc178ee19 100644
--- a/GDevelop.js/Bindings/Wrapper.cpp
+++ b/GDevelop.js/Bindings/Wrapper.cpp
@@ -53,7 +53,9 @@
 #include <GDCore/IDE/Events/ExampleExtensionUsagesFinder.h>
 #include <GDCore/IDE/EventsFunctionTools.h>
 #include <GDCore/IDE/EventsBasedObjectVariantHelper.h>
-#include <GDCore/IDE/EventsFunctionsExtensionExtractor.h>
+#include <GDCore/IDE/ExtensionEditor/ChildObjectForwardFunctionGenerator.h>
+#include <GDCore/IDE/ExtensionEditor/EventsFunctionsExtensionExtractor.h>
+#include <GDCore/IDE/ExtensionEditor/PropertyFunctionGenerator.h>
 #include <GDCore/IDE/ObjectRefactorer.h>
 #include <GDCore/IDE/Project/ArbitraryResourceWorker.h>
 #include <GDCore/IDE/Project/ArbitraryObjectsWorker.h>
@@ -65,7 +67,6 @@
 #include <GDCore/IDE/Project/ResourcesRenamer.h>
 #include <GDCore/IDE/Project/EventsBasedObjectDependencyFinder.h>
 #include <GDCore/IDE/ProjectBrowserHelper.h>
-#include <GDCore/IDE/PropertyFunctionGenerator.h>
 #include <GDCore/IDE/UnfilledRequiredBehaviorPropertyProblem.h>
 #include <GDCore/IDE/VariableInstructionSwitcher.h>
 #include <GDCore/IDE/WholeProjectRefactorer.h>
@@ -762,6 +763,9 @@ typedef std::vector<gd::PropertyDescriptorChoice> VectorPropertyDescriptorChoice
 #define STATIC_CanGenerateGetterAndSetter CanGenerateGetterAndSetter
 #define STATIC_GenerateConditionSkeleton GenerateConditionSkeleton
 #define STATIC_GenerateExpressionSkeleton GenerateExpressionSkeleton
+#define STATIC_GenerateChildObjectForwardFunctions GenerateChildObjectForwardFunctions
+#define STATIC_HasAnyChildCustomObject HasAnyChildCustomObject
+#define STATIC_GetChildCustomObjectNames GetChildCustomObjectNames
 #define STATIC_UpdateReturnActionType UpdateReturnActionType
 #define STATIC_CreateRectangle CreateRectangle
 #define STATIC_SanityCheckBehaviorProperty SanityCheckBehaviorProperty
diff --git a/GDevelop.js/types.d.ts b/GDevelop.js/types.d.ts
index 7c2eb3ea2e87..d9c57711dd7b 100644
--- a/GDevelop.js/types.d.ts
+++ b/GDevelop.js/types.d.ts
@@ -2268,6 +2268,12 @@ export class PropertyFunctionGenerator extends EmscriptenObject {
   static updateReturnActionType(project: Project, eventsFunction: EventsFunction): void;
 }
 
+export class ChildObjectForwardFunctionGenerator extends EmscriptenObject {
+  static generateChildObjectForwardFunctions(project: Project, extension: EventsFunctionsExtension, eventsBasedObject: EventsBasedObject, childObjectName: string): void;
+  static hasAnyChildCustomObject(project: Project, eventsBasedObject: EventsBasedObject): boolean;
+  static getChildCustomObjectNames(project: Project, eventsBasedObject: EventsBasedObject): VectorString;
+}
+
 export class UsedExtensionsResult extends EmscriptenObject {
   getUsedExtensions(): SetString;
 }
diff --git a/GDevelop.js/types/gdchildobjectforwardfunctiongenerator.js b/GDevelop.js/types/gdchildobjectforwardfunctiongenerator.js
new file mode 100644
index 000000000000..a304ca9b34ad
--- /dev/null
+++ b/GDevelop.js/types/gdchildobjectforwardfunctiongenerator.js
@@ -0,0 +1,8 @@
+// Automatically generated by GDevelop.js/scripts/generate-types.js
+declare class gdChildObjectForwardFunctionGenerator {
+  static generateChildObjectForwardFunctions(project: gdProject, extension: gdEventsFunctionsExtension, eventsBasedObject: gdEventsBasedObject, childObjectName: string): void;
+  static hasAnyChildCustomObject(project: gdProject, eventsBasedObject: gdEventsBasedObject): boolean;
+  static getChildCustomObjectNames(project: gdProject, eventsBasedObject: gdEventsBasedObject): gdVectorString;
+  delete(): void;
+  ptr: number;
+};
\ No newline at end of file
diff --git a/GDevelop.js/types/libgdevelop.js b/GDevelop.js/types/libgdevelop.js
index 9b7af1e07e6d..f752b4340dc2 100644
--- a/GDevelop.js/types/libgdevelop.js
+++ b/GDevelop.js/types/libgdevelop.js
@@ -214,6 +214,7 @@ declare class libGDevelop {
   ObjectTools: Class<gdObjectTools>;
   EventsBasedObjectDependencyFinder: Class<gdEventsBasedObjectDependencyFinder>;
   PropertyFunctionGenerator: Class<gdPropertyFunctionGenerator>;
+  ChildObjectForwardFunctionGenerator: Class<gdChildObjectForwardFunctionGenerator>;
   UsedExtensionsResult: Class<gdUsedExtensionsResult>;
   UsedExtensionsFinder: Class<gdUsedExtensionsFinder>;
   UsedObjectTypeFinder: Class<gdUsedObjectTypeFinder>;
diff --git a/newIDE/app/src/EventsFunctionsExtensionEditor/EventsBasedBehaviorOrObjectEditor/ChildObjectForwardFunctionGenerationDialog.js b/newIDE/app/src/EventsFunctionsExtensionEditor/EventsBasedBehaviorOrObjectEditor/ChildObjectForwardFunctionGenerationDialog.js
new file mode 100644
index 000000000000..74079da434fb
--- /dev/null
+++ b/newIDE/app/src/EventsFunctionsExtensionEditor/EventsBasedBehaviorOrObjectEditor/ChildObjectForwardFunctionGenerationDialog.js
@@ -0,0 +1,76 @@
+// @flow
+import { Trans } from '@lingui/macro';
+
+import * as React from 'react';
+import FlatButton from '../../UI/FlatButton';
+import RaisedButton from '../../UI/RaisedButton';
+import Text from '../../UI/Text';
+import Dialog from '../../UI/Dialog';
+import HelpButton from '../../UI/HelpButton';
+import ObjectSelector from '../../ObjectsList/ObjectSelector';
+import { ProjectScopedContainersAccessor } from '../../InstructionOrExpression/EventsScope';
+
+const excludedObjectOrGroupNames = ['Object'];
+
+type Props = {|
+  project: gdProject,
+  projectScopedContainersAccessor: ProjectScopedContainersAccessor,
+  onCancel: () => void,
+  onChoose: (childObjectName: string) => void,
+|};
+
+export default function ChildObjectForwardFunctionGenerationDialog({
+  project,
+  projectScopedContainersAccessor,
+  onChoose,
+  onCancel,
+}: Props): React.Node {
+  const [objectName, setObjectName] = React.useState('');
+
+  return (
+    <Dialog
+      title={<Trans>Choose an object</Trans>}
+      secondaryActions={[
+        <HelpButton
+          key="help"
+          helpPagePath="/objects/custom-objects-prefab-template"
+        />,
+      ]}
+      actions={[
+        <FlatButton
+          label={<Trans>Cancel</Trans>}
+          onClick={onCancel}
+          key={'close'}
+        />,
+        <RaisedButton
+          label={<Trans>Generate</Trans>}
+          primary
+          keyboardFocused={true}
+          onClick={() => onChoose(objectName)}
+          key={'generate'}
+        />,
+      ]}
+      open
+      onRequestClose={onCancel}
+      maxWidth="sm"
+    >
+      <Text>
+        <Trans>
+          Functions from this child-object will be forwarded by the parent.
+        </Trans>
+      </Text>
+      <ObjectSelector
+        project={project}
+        value={objectName}
+        excludedObjectOrGroupNames={excludedObjectOrGroupNames}
+        noGroups
+        requireCustomObject
+        onChange={setObjectName}
+        projectScopedContainersAccessor={projectScopedContainersAccessor}
+        floatingLabelText={<Trans>Choose an object</Trans>}
+        fullWidth
+        openOnFocus={false}
+      />
+    </Dialog>
+  );
+}
diff --git a/newIDE/app/src/EventsFunctionsExtensionEditor/EventsBasedBehaviorOrObjectEditor/EventsBasedObjectEditor.js b/newIDE/app/src/EventsFunctionsExtensionEditor/EventsBasedBehaviorOrObjectEditor/EventsBasedObjectEditor.js
index a769b1080811..f8d049f05002 100644
--- a/newIDE/app/src/EventsFunctionsExtensionEditor/EventsBasedBehaviorOrObjectEditor/EventsBasedObjectEditor.js
+++ b/newIDE/app/src/EventsFunctionsExtensionEditor/EventsBasedBehaviorOrObjectEditor/EventsBasedObjectEditor.js
@@ -18,12 +18,16 @@ import { CompactTextAreaField } from '../../UI/CompactTextAreaField';
 import CompactSemiControlledTextField from '../../UI/CompactSemiControlledTextField';
 import { CompactToggleField } from '../../UI/CompactToggleField';
 import { CompactIconField } from '../OptionsEditorDialog/CompactIconField';
+import { ProjectScopedContainersAccessor } from '../../InstructionOrExpression/EventsScope';
+import ChildObjectForwardFunctionGenerationDialog from './ChildObjectForwardFunctionGenerationDialog';
 
 const gd: libGDevelop = global.gd;
 
 const isDev = Window.isDev();
 
 type Props = {|
+  project: gdProject,
+  projectScopedContainersAccessor: ProjectScopedContainersAccessor,
   eventsFunctionsExtension: gdEventsFunctionsExtension,
   eventsBasedObject: gdEventsBasedObject,
   onOpenCustomObjectEditor: () => void,
@@ -34,6 +38,8 @@ type Props = {|
 |};
 
 export default function EventsBasedObjectEditor({
+  project,
+  projectScopedContainersAccessor,
   eventsFunctionsExtension,
   eventsBasedObject,
   onOpenCustomObjectEditor,
@@ -42,6 +48,10 @@ export default function EventsBasedObjectEditor({
 }: Props): React.Node {
   const forceUpdate = useForceUpdate();
   const [isLoading, setIsLoading] = React.useState(false);
+  const [
+    isChildObjectForwardFunctionGenerationDialogShown,
+    setChildObjectForwardFunctionGenerationDialogShown,
+  ] = React.useState(false);
 
   const onChange = React.useCallback(
     () => {
@@ -53,6 +63,22 @@ export default function EventsBasedObjectEditor({
     [forceUpdate, unsavedChanges]
   );
 
+  const generateChildObjectForwardFunctions = React.useCallback(
+    (childObjectName: string) => {
+      if (!childObjectName) {
+        return;
+      }
+      gd.ChildObjectForwardFunctionGenerator.generateChildObjectForwardFunctions(
+        project,
+        eventsFunctionsExtension,
+        eventsBasedObject,
+        childObjectName
+      );
+      onChange();
+    },
+    [eventsBasedObject, eventsFunctionsExtension, onChange, project]
+  );
+
   return (
     <I18n>
       {({ i18n }) => (
@@ -237,12 +263,46 @@ export default function EventsBasedObjectEditor({
               />
             </Line>
           )}
+          {gd.ChildObjectForwardFunctionGenerator.hasAnyChildCustomObject(
+            project,
+            eventsBasedObject
+          ) ? (
+            <AlertMessage
+              kind="info"
+              renderRightButton={() => (
+                <RaisedButton
+                  label={<Trans>Generate functions</Trans>}
+                  onClick={() =>
+                    setChildObjectForwardFunctionGenerationDialogShown(true)
+                  }
+                />
+              )}
+            >
+              <Trans>
+                Some functions can be generated to forward child-object's
+                functions.
+              </Trans>
+            </AlertMessage>
+          ) : null}
           <Line noMargin>
             <HelpButton
               key="help"
               helpPagePath="/objects/custom-objects-prefab-template"
             />
           </Line>
+          {isChildObjectForwardFunctionGenerationDialogShown && (
+            <ChildObjectForwardFunctionGenerationDialog
+              project={project}
+              projectScopedContainersAccessor={projectScopedContainersAccessor}
+              onChoose={childObjectName => {
+                generateChildObjectForwardFunctions(childObjectName);
+                setChildObjectForwardFunctionGenerationDialogShown(false);
+              }}
+              onCancel={() =>
+                setChildObjectForwardFunctionGenerationDialogShown(false)
+              }
+            />
+          )}
         </ColumnStackLayout>
       )}
     </I18n>
diff --git a/newIDE/app/src/EventsFunctionsExtensionEditor/EventsBasedBehaviorOrObjectEditor/index.js b/newIDE/app/src/EventsFunctionsExtensionEditor/EventsBasedBehaviorOrObjectEditor/index.js
index 199105e96169..b15aaecc7079 100644
--- a/newIDE/app/src/EventsFunctionsExtensionEditor/EventsBasedBehaviorOrObjectEditor/index.js
+++ b/newIDE/app/src/EventsFunctionsExtensionEditor/EventsBasedBehaviorOrObjectEditor/index.js
@@ -205,6 +205,10 @@ export const EventsBasedBehaviorOrObjectEditor: React.ComponentType<{
                   />
                 ) : eventsBasedObject ? (
                   <EventsBasedObjectEditor
+                    project={project}
+                    projectScopedContainersAccessor={
+                      projectScopedContainersAccessor
+                    }
                     eventsFunctionsExtension={eventsFunctionsExtension}
                     eventsBasedObject={eventsBasedObject}
                     unsavedChanges={unsavedChanges}
diff --git a/newIDE/app/src/EventsSheet/ParameterFields/GlobalVariableField.js b/newIDE/app/src/EventsSheet/ParameterFields/GlobalVariableField.js
index 7409b6a98dd5..cc9f0915c28c 100644
--- a/newIDE/app/src/EventsSheet/ParameterFields/GlobalVariableField.js
+++ b/newIDE/app/src/EventsSheet/ParameterFields/GlobalVariableField.js
@@ -62,6 +62,7 @@ export default (React.forwardRef<ParameterFieldProps, ParameterFieldInterface>(
           openVariableEditorDialog={setVariableEditorOpen}
           globalObjectsContainer={props.globalObjectsContainer}
           objectsContainer={props.objectsContainer}
+          project={project}
           projectScopedContainersAccessor={projectScopedContainersAccessor}
           scope={scope}
           getVariableSourceFromIdentifier={getVariableSourceFromIdentifier}
diff --git a/newIDE/app/src/EventsSheet/ParameterFields/ParameterFieldCommons.js b/newIDE/app/src/EventsSheet/ParameterFields/ParameterFieldCommons.js
index 114d7db1a35a..fda09cf786c6 100644
--- a/newIDE/app/src/EventsSheet/ParameterFields/ParameterFieldCommons.js
+++ b/newIDE/app/src/EventsSheet/ParameterFields/ParameterFieldCommons.js
@@ -20,7 +20,7 @@ type CommonProps = {|
   value: string,
 
   // Context
-  project?: gdProject,
+  project: gdProject,
   scope: EventsScope,
   globalObjectsContainer: gdObjectsContainer,
   objectsContainer: gdObjectsContainer,
diff --git a/newIDE/app/src/EventsSheet/ParameterFields/SceneVariableField.js b/newIDE/app/src/EventsSheet/ParameterFields/SceneVariableField.js
index 421e9855a468..e56e22b2051c 100644
--- a/newIDE/app/src/EventsSheet/ParameterFields/SceneVariableField.js
+++ b/newIDE/app/src/EventsSheet/ParameterFields/SceneVariableField.js
@@ -89,6 +89,7 @@ export default (React.forwardRef<ParameterFieldProps, ParameterFieldInterface>(
           openVariableEditorDialog={setVariableEditorOpen}
           globalObjectsContainer={props.globalObjectsContainer}
           objectsContainer={props.objectsContainer}
+          project={project}
           projectScopedContainersAccessor={projectScopedContainersAccessor}
           scope={scope}
           id={
diff --git a/newIDE/app/src/ObjectGroupEditor/index.js b/newIDE/app/src/ObjectGroupEditor/index.js
index f197f89847ce..fa2a50056885 100644
--- a/newIDE/app/src/ObjectGroupEditor/index.js
+++ b/newIDE/app/src/ObjectGroupEditor/index.js
@@ -18,7 +18,7 @@ const styles = {
 };
 
 type Props = {|
-  project: ?gdProject,
+  project: gdProject,
   projectScopedContainersAccessor: ProjectScopedContainersAccessor,
   globalObjectsContainer: gdObjectsContainer | null,
   objectsContainer: gdObjectsContainer,
diff --git a/newIDE/app/src/ObjectsList/CompactObjectSelector.js b/newIDE/app/src/ObjectsList/CompactObjectSelector.js
index 21f464621d4b..b609bd6027cf 100644
--- a/newIDE/app/src/ObjectsList/CompactObjectSelector.js
+++ b/newIDE/app/src/ObjectsList/CompactObjectSelector.js
@@ -18,7 +18,7 @@ import CompactPropertiesEditorRowField from '../CompactPropertiesEditor/CompactP
 const gd: libGDevelop = global.gd;
 
 type Props = {|
-  project: ?gdProject,
+  project: gdProject,
   projectScopedContainersAccessor: ProjectScopedContainersAccessor,
 
   /** If specified, only this object type should be allowed to be selected. */
@@ -38,6 +38,8 @@ type Props = {|
   /** A list of object names to exclude from the autocomplete list (for example if they have already been selected). */
   excludedObjectOrGroupNames?: Array<string>,
 
+  requireCustomObject?: boolean,
+
   onChoose?: string => void,
   onChange: string => void,
   onRequestClose?: () => void,
@@ -62,6 +64,7 @@ const CompactObjectSelector = (props: Props): React.Node => {
     project,
     projectScopedContainersAccessor,
     allowedObjectType,
+    requireCustomObject,
     noGroups,
     errorTextIfInvalid,
     onRequestClose,
@@ -88,6 +91,7 @@ const CompactObjectSelector = (props: Props): React.Node => {
         allowedObjectType,
         requiredCapabilitiesBehaviorTypes,
         excludedObjectOrGroupNames,
+        requireCustomObject,
       });
     },
     [
@@ -96,6 +100,7 @@ const CompactObjectSelector = (props: Props): React.Node => {
       noGroups,
       project,
       projectScopedContainersAccessor,
+      requireCustomObject,
       requiredCapabilitiesBehaviorTypes,
     ]
   );
diff --git a/newIDE/app/src/ObjectsList/ObjectSelector.js b/newIDE/app/src/ObjectsList/ObjectSelector.js
index 0851d00881e2..3a8d2366c87e 100644
--- a/newIDE/app/src/ObjectsList/ObjectSelector.js
+++ b/newIDE/app/src/ObjectsList/ObjectSelector.js
@@ -19,7 +19,7 @@ import { ProjectScopedContainersAccessor } from '../InstructionOrExpression/Even
 const gd: libGDevelop = global.gd;
 
 type Props = {|
-  project: ?gdProject,
+  project: gdProject,
   projectScopedContainersAccessor: ProjectScopedContainersAccessor,
 
   /** If specified, only this object type should be allowed to be selected. */
@@ -39,6 +39,8 @@ type Props = {|
   /** A list of object names to exclude from the autocomplete list (for example if they have already been selected). */
   excludedObjectOrGroupNames?: Array<string>,
 
+  requireCustomObject?: boolean,
+
   onChoose?: string => void,
   onChange: string => void,
   onRequestClose?: () => void,
@@ -66,19 +68,28 @@ export const getObjectsAndGroupsDataSource = ({
   allowedObjectType,
   requiredCapabilitiesBehaviorTypes,
   excludedObjectOrGroupNames,
+  requireCustomObject,
 }: {|
-  project: ?gdProject,
+  project: gdProject,
   objectsContainersList: gdObjectsContainersList,
   noGroups: ?boolean,
   allowedObjectType: ?string,
   requiredCapabilitiesBehaviorTypes?: Array<string>,
   excludedObjectOrGroupNames: ?Array<string>,
+  requireCustomObject: ?boolean,
 |}): DataSource => {
-  const { allObjectsList, allGroupsList } = enumerateObjectsAndGroups(
+  let { allObjectsList, allGroupsList } = enumerateObjectsAndGroups(
     objectsContainersList,
     allowedObjectType || undefined,
     requiredCapabilitiesBehaviorTypes || []
   );
+
+  allObjectsList = requireCustomObject
+    ? allObjectsList.filter(({ object }) =>
+        project.hasEventsBasedObject(object.getType())
+      )
+    : allObjectsList;
+
   const objects = allObjectsList.map(({ object }) => {
     return {
       text: object.getName(),
@@ -105,19 +116,20 @@ export const getObjectsAndGroupsDataSource = ({
         };
       });
 
-  const fullList =
+  let fullList =
     groups.length === 0
       ? objects
       : [...objects, { type: 'separator' }, ...groups];
 
-  return excludedObjectOrGroupNames
-    ? // $FlowFixMe[incompatible-type]
-      fullList.filter(
+  fullList = excludedObjectOrGroupNames
+    ? fullList.filter(
         //$FlowFixMe[incompatible-type]
         ({ value }) => !excludedObjectOrGroupNames.includes(value)
       )
-    : // $FlowFixMe[incompatible-type]
-      fullList;
+    : fullList;
+
+  // $FlowFixMe[incompatible-type]
+  return fullList;
 };
 
 export const checkHasRequiredBehaviors = ({
@@ -193,6 +205,7 @@ const ObjectSelector: React.ComponentType<{
     onApply,
     id,
     excludedObjectOrGroupNames,
+    requireCustomObject,
     hintText,
     requiredCapabilitiesBehaviorTypes,
     requiredVisibleBehaviorTypes,
@@ -211,6 +224,7 @@ const ObjectSelector: React.ComponentType<{
     allowedObjectType,
     requiredCapabilitiesBehaviorTypes,
     excludedObjectOrGroupNames,
+    requireCustomObject,
   });
 
   const hasValidChoice =
diff --git a/newIDE/app/src/fixtures/TestProject.js b/newIDE/app/src/fixtures/TestProject.js
index 42e33f5781dc..e7cee0eb1314 100644
--- a/newIDE/app/src/fixtures/TestProject.js
+++ b/newIDE/app/src/fixtures/TestProject.js
@@ -45,6 +45,9 @@ export type TestProject = {|
   testBehaviorEventsFunction: gdEventsFunction,
   testBehaviorLifecycleEventsFunction: gdEventsFunction,
   testEventsBasedObject: gdEventsBasedObject,
+  composedEventBasedObject: gdEventsBasedObject,
+  eventBasedObjectProjectScopedContainersAccessor: ProjectScopedContainersAccessor,
+  composedEventBasedObjectProjectScopedContainersAccessor: ProjectScopedContainersAccessor,
   testObjectEventsFunction: gdEventsFunction,
   layerWithEffects: gdLayer,
   layerWith3DEffects: gdLayer,
@@ -182,6 +185,30 @@ export const makeTestProject = (gd /*: libGDevelop */) /*: TestProject */ => {
     .getEvents()
     .insertNewEvent(project, 'BuiltinCommonInstructions::Standard', 0);
 
+  const composedEventBasedObject = buttonExtension
+    .getEventsBasedObjects()
+    .insertNew('ComposedEventBasedObject', 0);
+  composedEventBasedObject
+    .getObjects()
+    .insertNewObject(project, 'Button::PanelSpriteButton', 'Button', 0);
+
+  const eventBasedObjectProjectScopedContainersAccessor = new ProjectScopedContainersAccessor(
+    {
+      project,
+      eventsFunctionsExtension: buttonExtension,
+      eventsBasedObject: buttonEventBasedObject,
+    },
+    new gd.ObjectsContainer(gd.ObjectsContainer.Function)
+  );
+  const composedEventBasedObjectProjectScopedContainersAccessor = new ProjectScopedContainersAccessor(
+    {
+      project,
+      eventsFunctionsExtension: buttonExtension,
+      eventsBasedObject: composedEventBasedObject,
+    },
+    new gd.ObjectsContainer(gd.ObjectsContainer.Function)
+  );
+
   // Create and expose some objects
   const testLayout = project.insertNewLayout('TestLayout', 0);
   const customObject = testLayout
@@ -1013,6 +1040,9 @@ export const makeTestProject = (gd /*: libGDevelop */) /*: TestProject */ => {
     testBehaviorEventsFunction,
     testBehaviorLifecycleEventsFunction,
     testEventsBasedObject: buttonEventBasedObject,
+    composedEventBasedObject,
+    eventBasedObjectProjectScopedContainersAccessor,
+    composedEventBasedObjectProjectScopedContainersAccessor,
     testObjectEventsFunction,
     layerWithEffects,
     layerWith3DEffects,
diff --git a/newIDE/app/src/stories/componentStories/EventsBasedObjectEditor/EventsBasedObjectEditor.stories.js b/newIDE/app/src/stories/componentStories/EventsBasedObjectEditor/EventsBasedObjectEditor.stories.js
index 0345dffa701a..515367f37f58 100644
--- a/newIDE/app/src/stories/componentStories/EventsBasedObjectEditor/EventsBasedObjectEditor.stories.js
+++ b/newIDE/app/src/stories/componentStories/EventsBasedObjectEditor/EventsBasedObjectEditor.stories.js
@@ -17,6 +17,10 @@ export default {
 
 export const Default = (): React.Node => (
   <EventsBasedObjectEditor
+    projectScopedContainersAccessor={
+      testProject.eventBasedObjectProjectScopedContainersAccessor
+    }
+    project={testProject.project}
     eventsFunctionsExtension={testProject.testEventsFunctionsExtension}
     eventsBasedObject={testProject.testEventsBasedObject}
     onOpenCustomObjectEditor={action('onOpenCustomObjectEditor')}
@@ -25,3 +29,18 @@ export const Default = (): React.Node => (
     )}
   />
 );
+
+export const WithChildCustomObject = (): React.Node => (
+  <EventsBasedObjectEditor
+    projectScopedContainersAccessor={
+      testProject.composedEventBasedObjectProjectScopedContainersAccessor
+    }
+    project={testProject.project}
+    eventsFunctionsExtension={testProject.testEventsFunctionsExtension}
+    eventsBasedObject={testProject.composedEventBasedObject}
+    onOpenCustomObjectEditor={action('onOpenCustomObjectEditor')}
+    onEventsBasedObjectChildrenEdited={action(
+      'onEventsBasedObjectChildrenEdited'
+    )}
+  />
+);
diff --git a/newIDE/app/src/stories/componentStories/ParameterFields/OperatorField.stories.js b/newIDE/app/src/stories/componentStories/ParameterFields/OperatorField.stories.js
index eb5e17604d1d..b946709de22f 100644
--- a/newIDE/app/src/stories/componentStories/ParameterFields/OperatorField.stories.js
+++ b/newIDE/app/src/stories/componentStories/ParameterFields/OperatorField.stories.js
@@ -19,6 +19,7 @@ export const OperatorFieldString = (): React.Node => (
     initialValue=""
     render={(value, onChange) => (
       <OperatorField
+        project={testProject.project}
         scope={{ project: testProject.project }}
         value={value}
         onChange={onChange}
@@ -39,6 +40,7 @@ export const OperatorFieldNumber = (): React.Node => (
     initialValue=""
     render={(value, onChange) => (
       <OperatorField
+        project={testProject.project}
         scope={{ project: testProject.project }}
         value={value}
         onChange={onChange}
@@ -59,6 +61,7 @@ export const OperatorFieldColor = (): React.Node => (
     initialValue=""
     render={(value, onChange) => (
       <OperatorField
+        project={testProject.project}
         scope={{ project: testProject.project }}
         value={value}
         onChange={onChange}
@@ -77,6 +80,7 @@ export const OperatorFieldUnknownType = (): React.Node => (
     initialValue=""
     render={(value, onChange) => (
       <OperatorField
+        project={testProject.project}
         scope={{ project: testProject.project }}
         value={value}
         onChange={onChange}
diff --git a/newIDE/app/src/stories/componentStories/RelationalOperatorField.stories.js b/newIDE/app/src/stories/componentStories/RelationalOperatorField.stories.js
index 4fd91166ee84..c730a89e41fb 100644
--- a/newIDE/app/src/stories/componentStories/RelationalOperatorField.stories.js
+++ b/newIDE/app/src/stories/componentStories/RelationalOperatorField.stories.js
@@ -19,6 +19,7 @@ export const RelationalOperatorFieldString = (): React.Node => (
     initialValue=""
     render={(value, onChange) => (
       <RelationalOperatorField
+        project={testProject.project}
         scope={{ project: testProject.project }}
         value={value}
         onChange={onChange}
@@ -39,6 +40,7 @@ export const RelationalOperatorFieldNumber = (): React.Node => (
     initialValue=""
     render={(value, onChange) => (
       <RelationalOperatorField
+        project={testProject.project}
         scope={{ project: testProject.project }}
         value={value}
         onChange={onChange}
@@ -59,6 +61,7 @@ export const RelationalOperatorFieldColor = (): React.Node => (
     initialValue=""
     render={(value, onChange) => (
       <RelationalOperatorField
+        project={testProject.project}
         scope={{ project: testProject.project }}
         value={value}
         onChange={onChange}
@@ -77,6 +80,7 @@ export const RelationalOperatorFieldUnknownType = (): React.Node => (
     initialValue=""
     render={(value, onChange) => (
       <RelationalOperatorField
+        project={testProject.project}
         scope={{ project: testProject.project }}
         value={value}
         onChange={onChange}
diff --git a/newIDE/app/src/stories/everything-else.stories.js b/newIDE/app/src/stories/everything-else.stories.js
index 65fc284c3f5c..31a0fee20451 100644
--- a/newIDE/app/src/stories/everything-else.stories.js
+++ b/newIDE/app/src/stories/everything-else.stories.js
@@ -1205,6 +1205,7 @@ storiesOf('ParameterFields', module)
       initialValue={'"GUI"'}
       render={(value, onChange) => (
         <LayerField
+          project={testProject.project}
           scope={{ project: testProject.project }}
           value={value}
           onChange={onChange}
@@ -1243,6 +1244,7 @@ storiesOf('ParameterFields', module)
       initialValue={'"TestLayout"'}
       render={(value, onChange) => (
         <SceneNameField
+          project={testProject.project}
           scope={{ project: testProject.project }}
           value={value}
           onChange={onChange}
@@ -1317,6 +1319,7 @@ storiesOf('ParameterFields', module)
       initialValue={'Variable1'}
       render={(value, onChange) => (
         <SceneVariableField
+          project={testProject.project}
           scope={{ project: testProject.project }}
           value={value}
           onChange={onChange}
@@ -1334,6 +1337,7 @@ storiesOf('ParameterFields', module)
       initialValue={'Variable1'}
       render={(value, onChange) => (
         <ObjectVariableField
+          project={testProject.project}
           scope={{ project: testProject.project }}
           value={value}
           onChange={onChange}
@@ -1351,6 +1355,7 @@ storiesOf('ParameterFields', module)
       initialValue={'"123;342;345"'}
       render={(value, onChange) => (
         <ColorExpressionField
+          project={testProject.project}
           scope={{ project: testProject.project }}
           value={value}
           onChange={onChange}
@@ -1368,6 +1373,7 @@ storiesOf('ParameterFields', module)
       initialValue={'"123;342;345"'}
       render={(value, onChange) => (
         <ColorExpressionField
+          project={testProject.project}
           scope={{ project: testProject.project }}
           value={value}
           onChange={onChange}
@@ -1386,6 +1392,7 @@ storiesOf('ParameterFields', module)
       initialValue={''}
       render={(value, onChange) => (
         <TrueFalseField
+          project={testProject.project}
           scope={{ project: testProject.project }}
           value={value}
           onChange={onChange}
@@ -1404,6 +1411,7 @@ storiesOf('ParameterFields', module)
       initialValue={''}
       render={(value, onChange) => (
         <YesNoField
+          project={testProject.project}
           scope={{ project: testProject.project }}
           value={value}
           onChange={onChange}
@@ -1422,6 +1430,7 @@ storiesOf('ParameterFields', module)
       initialValue={''}
       render={(value, onChange) => (
         <ForceMultiplierField
+          project={testProject.project}
           scope={{ project: testProject.project }}
           value={value}
           onChange={onChange}
@@ -1439,6 +1448,7 @@ storiesOf('ParameterFields', module)
       initialValue={'0.8'}
       render={(value, onChange) => (
         <ForceMultiplierField
+          project={testProject.project}
           scope={{ project: testProject.project }}
           value={value}
           onChange={onChange}