diff --git a/core/src/objects/base/instance.cpp b/core/src/objects/base/instance.cpp
index 1cd287d..9f6e5d5 100644
--- a/core/src/objects/base/instance.cpp
+++ b/core/src/objects/base/instance.cpp
@@ -25,13 +25,23 @@ const InstanceType Instance::TYPE = {
 //     return &TYPE_;
 // }
 
+constexpr FieldCodec classNameCodec() {
+    return FieldCodec {
+        .write = nullptr,
+        .read = [](void* source) -> Data::Variant {
+            return Data::String(((const InstanceType*)source)->className);
+        },
+    };
+}
+
 Instance::Instance(const InstanceType* type) {
     this->name = type->className;
 
     this->memberMap = std::make_unique<MemberMap>( MemberMap {
         .super = std::nullopt,
         .members = {
-            { "Name", { .backingField = &name, .type = &Data::String::TYPE, .codec = fieldCodecOf<Data::String, std::string>() } }
+            { "Name", { .backingField = &name, .type = &Data::String::TYPE, .codec = fieldCodecOf<Data::String, std::string>() } },
+            { "ClassName", { .backingField = const_cast<InstanceType*>(type), .type = &Data::String::TYPE, .codec = classNameCodec(), .flags = PROP_READONLY } },
         }
     });
 }
@@ -156,7 +166,7 @@ auto meta = GetPropertyMeta(name);
 
 tl::expected<void, MemberNotFound> Instance::SetPropertyValue(std::string name, Data::Variant value) {
     auto meta = GetPropertyMeta(name);
-    if (!meta) return tl::make_unexpected(MemberNotFound());
+    if (!meta || meta->flags & PROP_READONLY) return tl::make_unexpected(MemberNotFound());
 
     meta->codec.write(value, meta->backingField);
     if (meta->updateCallback) meta->updateCallback.value()(name);
diff --git a/core/src/objects/base/member.h b/core/src/objects/base/member.h
index 5306eab..b0a1ecf 100644
--- a/core/src/objects/base/member.h
+++ b/core/src/objects/base/member.h
@@ -48,11 +48,12 @@ enum PropertyFlags {
     PROP_HIDDEN = 1 << 0, // Hidden from the editor
     PROP_NOSAVE = 1 << 1, // Do not serialize
     PROP_UNIT_FLOAT = 1 << 2, // Float between 0 and 1
+    PROP_READONLY = 1 << 3, // Read only property, do not write
 };
 
 enum PropertyCategory {
-    PROP_CATEGORY_DATA,
     PROP_CATEGORY_APPEARENCE,
+    PROP_CATEGORY_DATA,
     PROP_CATEGORY_BEHAVIOR,
     PROP_CATEGORY_PART,
     PROP_CATEGORY_SURFACE,