diff --git a/src/blackmisc/variant.cpp b/src/blackmisc/variant.cpp
index a5a2f9dc2..7d0ab72ca 100644
--- a/src/blackmisc/variant.cpp
+++ b/src/blackmisc/variant.cpp
@@ -205,6 +205,48 @@ namespace BlackMisc
         }
     }
 
+    QJsonObject CVariant::toMemoizedJson() const
+    {
+        auto *meta = getValueObjectMetaInfo();
+        if (meta)
+        {
+            try
+            {
+                QJsonObject json;
+                json.insert("type", this->typeName());
+                json.insert("value", meta->toMemoizedJson(data()));
+                return json;
+            }
+            catch (const Private::CVariantException &ex)
+            {
+                CLogMessage(this).debug() << ex.what();
+                return {};
+            }
+        }
+        else
+        {
+            return toJson();
+        }
+    }
+
+    void CVariant::convertFromMemoizedJson(const QJsonObject &json)
+    {
+        QString typeName = json.value("type").toString();
+        if (typeName.isEmpty()) { m_v.clear(); return; }
+        int typeId = QMetaType::type(qPrintable(typeName));
+
+        auto *meta = Private::getValueObjectMetaInfo(typeId);
+        if (meta)
+        {
+            m_v = QVariant(typeId, nullptr);
+            meta->convertFromMemoizedJson(json.value("value").toObject(), data());
+        }
+        else
+        {
+            convertFromJson(json);
+        }
+    }
+
     uint CVariant::getValueHash() const
     {
         switch (m_v.type())
diff --git a/src/blackmisc/variant.h b/src/blackmisc/variant.h
index 637c3abec..857559cdb 100644
--- a/src/blackmisc/variant.h
+++ b/src/blackmisc/variant.h
@@ -277,6 +277,12 @@ namespace BlackMisc
         //! \copydoc BlackMisc::Mixin::JsonByMetaClass::convertFromJson
         void convertFromJson(const QJsonObject &json);
 
+        //! To compact JSON format.
+        QJsonObject toMemoizedJson() const;
+
+        //! From compact JSON format.
+        void convertFromMemoizedJson(const QJsonObject &json);
+
         //! \copydoc BlackMisc::Mixin::DBusByMetaClass::marshallToDbus
         void marshallToDbus(QDBusArgument &argument) const;
 
diff --git a/src/blackmisc/variantmap.cpp b/src/blackmisc/variantmap.cpp
index 8915e9dd3..652d57ef8 100644
--- a/src/blackmisc/variantmap.cpp
+++ b/src/blackmisc/variantmap.cpp
@@ -54,4 +54,44 @@ namespace BlackMisc
         }
     }
 
+    QJsonObject &CVariantMap::mergeToMemoizedJson(QJsonObject &json) const
+    {
+        for (auto it = cbegin(); it != cend(); ++it)
+        {
+            json.insert(it.key(), it.value().toMemoizedJson());
+        }
+        return json;
+    }
+
+    QJsonObject CVariantMap::toMemoizedJson() const
+    {
+        QJsonObject json;
+        mergeToMemoizedJson(json);
+        return json;
+    }
+
+    void CVariantMap::convertFromMemoizedJson(const QJsonObject &json)
+    {
+        clear();
+        for (auto it = json.begin(); it != json.end(); ++it)
+        {
+            CVariant value;
+            value.convertFromMemoizedJson(it.value().toObject());
+            implementationOf(*this).insert(cend(), it.key(), value);
+        }
+    }
+
+    void CVariantMap::convertFromMemoizedJson(const QJsonObject &json, const QStringList &keys)
+    {
+        clear();
+        for (const auto &key : keys)
+        {
+            auto value = json.value(key);
+            if (value.isUndefined()) { continue; }
+            CVariant var;
+            var.convertFromMemoizedJson(value.toObject());
+            insert(key, var);
+        }
+    }
+
 }
diff --git a/src/blackmisc/variantmap.h b/src/blackmisc/variantmap.h
index 09a2aa118..fb4f07c81 100644
--- a/src/blackmisc/variantmap.h
+++ b/src/blackmisc/variantmap.h
@@ -68,6 +68,19 @@ namespace BlackMisc
         //! \copydoc BlackMisc::CValueObject::convertFromJson
         //! Convert only keys present in list argument.
         void convertFromJson(const QJsonObject &json, const QStringList &keys);
+
+        //! Insert values from this map into an existing compact JSON object.
+        QJsonObject &mergeToMemoizedJson(QJsonObject &json) const;
+
+        //! To compact JSON format.
+        QJsonObject toMemoizedJson() const;
+
+        //! From compact JSON format.
+        void convertFromMemoizedJson(const QJsonObject &json);
+
+        //! From compact JSON format.
+        //! Convert only keys present in list argument.
+        void convertFromMemoizedJson(const QJsonObject &json, const QStringList &keys);
     };
 
 }
diff --git a/src/blackmisc/variantprivate.h b/src/blackmisc/variantprivate.h
index f8709ff0a..88ed7eb83 100644
--- a/src/blackmisc/variantprivate.h
+++ b/src/blackmisc/variantprivate.h
@@ -46,6 +46,8 @@ namespace BlackMisc
             virtual QString toQString(const void *object, bool i18n) const = 0;
             virtual QJsonObject toJson(const void *object) const = 0;
             virtual void convertFromJson(const QJsonObject &json, void *object) const = 0;
+            virtual QJsonObject toMemoizedJson(const void *object) const = 0;
+            virtual void convertFromMemoizedJson(const QJsonObject &json, void *object) const = 0;
             virtual void unmarshall(const QDBusArgument &arg, void *object) const = 0;
             virtual uint getValueHash(const void *object) const = 0;
             virtual int getMetaTypeId() const = 0;
@@ -93,6 +95,16 @@ namespace BlackMisc
             template <typename T>
             static void convertFromJson(const QJsonObject &, T &object, ...) { throw CVariantException(object, "convertFromJson"); }
 
+            template <typename T>
+            static QJsonObject toMemoizedJson(const T &object, decltype(static_cast<void>(object.toMemoizedJson()), 0)) { return object.toMemoizedJson(); }
+            template <typename T>
+            static QJsonObject toMemoizedJson(const T &object, ...) { return toJson(object, 0); }
+
+            template <typename T>
+            static void convertFromMemoizedJson(const QJsonObject &json, T &object, decltype(static_cast<void>(object.convertFromMemoizedJson(json)), 0)) { object.convertFromMemoizedJson(json); }
+            template <typename T>
+            static void convertFromMemoizedJson(const QJsonObject &json, T &object, ...) { convertFromJson(json, object, 0); }
+
             template <typename T>
             static uint getValueHash(const T &object, decltype(static_cast<void>(qHash(object)), 0)) { return qHash(object); }
             template <typename T>
@@ -145,6 +157,14 @@ namespace BlackMisc
             {
                 CValueObjectMetaInfoHelper::convertFromJson(json, cast(object), 0);
             }
+            virtual QJsonObject toMemoizedJson(const void *object) const override
+            {
+                return CValueObjectMetaInfoHelper::toMemoizedJson(cast(object), 0);
+            }
+            virtual void convertFromMemoizedJson(const QJsonObject &json, void *object) const override
+            {
+                CValueObjectMetaInfoHelper::convertFromMemoizedJson(json, cast(object), 0);
+            }
             virtual void unmarshall(const QDBusArgument &arg, void *object) const override
             {
                 arg >> cast(object);