diff --git a/kgql-compiler/src/main/kotlin/com/codingfeline/kgql/compiler/generator/VariablesWrapperGenerator2.kt b/kgql-compiler/src/main/kotlin/com/codingfeline/kgql/compiler/generator/VariablesWrapperGenerator2.kt
new file mode 100644
index 0000000..084f888
--- /dev/null
+++ b/kgql-compiler/src/main/kotlin/com/codingfeline/kgql/compiler/generator/VariablesWrapperGenerator2.kt
@@ -0,0 +1,185 @@
+package com.codingfeline.kgql.compiler.generator
+
+import com.codingfeline.kgql.compiler.KgqlCustomTypeMapper
+import com.codingfeline.kgql.core.internal.KgqlValue
+import com.squareup.kotlinpoet.ClassName
+import com.squareup.kotlinpoet.CodeBlock
+import com.squareup.kotlinpoet.FunSpec
+import com.squareup.kotlinpoet.MemberName
+import com.squareup.kotlinpoet.ParameterSpec
+import com.squareup.kotlinpoet.ParameterizedTypeName.Companion.plusParameter
+import com.squareup.kotlinpoet.PropertySpec
+import com.squareup.kotlinpoet.TypeName
+import com.squareup.kotlinpoet.TypeSpec
+import com.squareup.kotlinpoet.asTypeName
+import com.squareup.kotlinpoet.buildCodeBlock
+import graphql.language.VariableDefinition
+import kotlinx.serialization.internal.EnumSerializer
+import kotlinx.serialization.json.Json
+import kotlinx.serialization.json.JsonObject
+
+private const val VARIABLES_CLASS_NAME = "Variables"
+
+class VariablesWrapperGenerator2(
+    private val variables: List<VariableDefinition>,
+    private val parentObjectName: ClassName,
+    private val typeMapper: KgqlCustomTypeMapper
+) {
+    private val classifiedVariables = variables.map { VariableType.classify(it, typeMapper) }
+
+    fun generateType(): TypeSpec {
+        val classSpec = TypeSpec.classBuilder(VARIABLES_CLASS_NAME)
+            .primaryConstructor(generateConstructor(classifiedVariables))
+            .addProperties(generateProperties(classifiedVariables))
+            .addFunctions(generateSetterFunctions(classifiedVariables))
+
+        generateAsJsonObjectFunction(classifiedVariables, classSpec.propertySpecs.associateBy { it.name })
+
+        return classSpec.build()
+    }
+
+    private fun generateConstructor(variables: List<VariableType>): FunSpec {
+        return FunSpec.constructorBuilder()
+            .addParameters(
+                // constructor parameters must be required type without default value.
+                variables.filter { it is VariableType.Required }
+                    .map {
+                        ParameterSpec.builder(it.definition.name, it.type).build()
+                    }
+            )
+            .build()
+    }
+
+    private fun generateProperties(variables: List<VariableType>): List<PropertySpec> {
+        return variables.map { def -> def.generateProperty() }
+    }
+
+    private fun generateSetterFunctions(variables: List<VariableType>): List<FunSpec> {
+        return variables.filter { it !is VariableType.Required }.map { it.generateSetterFunction(parentObjectName) }
+    }
+
+    private fun generateAsJsonObjectFunction(
+        variables: List<VariableType>,
+        properties: Map<String, PropertySpec>
+    ): FunSpec {
+        return FunSpec.builder("asJsonObject")
+            .returns(JsonObject::class)
+            .addCode(
+                buildCodeBlock {
+                    val jsonFun = MemberName("kotlinx.serialization.json", "json")
+                    val isEnumSubclass = MemberName("com.codingfeline.kgql.core.internal", "isEnumSubClass")
+                    beginControlFlow("%M", jsonFun)
+                    variables.forEach { variable ->
+                        val name = variable.definition.name
+                        val property = properties[name]
+                        if (variable is VariableType.Required) {
+                            when (variable.type.copy(nullable = false)) {
+                                String::class.asTypeName(),
+                                Int::class.asTypeName(),
+                                Float::class.asTypeName() -> {
+                                    addStatement(
+                                        "%S to %N",
+                                        name,
+                                        property
+                                    )
+                                }
+                                else -> {
+                                    beginControlFlow("val serializer = if (%M(%N))", isEnumSubclass, property)
+                                    addStatement("%T", EnumSerializer::class.asTypeName())
+                                    nextControlFlow("else")
+
+                                    endControlFlow()
+
+                                    addStatement(
+                                        "%S to %T.plain.toJson(%T.serializer(), %N)",
+                                        name,
+                                        Json::class,
+                                        variable.type,
+                                        property
+                                    )
+                                }
+                            }
+                        } else {
+                            variable.definition.type
+                        }
+                    }
+                    endControlFlow()
+                }
+            )
+            .build()
+    }
+
+    sealed class VariableType {
+        abstract val definition: VariableDefinition
+        abstract val type: TypeName
+
+        open fun generateProperty(): PropertySpec {
+            return PropertySpec.builder(definition.name, KgqlValue::class.asTypeName().plusParameter(type))
+                .initializer("%T", KgqlValue.None)
+                .build()
+        }
+
+        open fun generateSetterFunction(parentObjectName: ClassName): FunSpec {
+            val param = ParameterSpec.builder(definition.name, type).build()
+            return FunSpec.builder(definition.name)
+                .addParameter(param)
+                .returns(parentObjectName.nestedClass(VARIABLES_CLASS_NAME))
+                .addCode(
+                    CodeBlock.builder()
+                        .addStatement("this.${definition.name} = %T(%N)", KgqlValue.Some::class, param)
+                        .addStatement("return this")
+                        .build()
+                )
+                .build()
+        }
+
+        open fun appendStatementForAsJsonObject(builder: CodeBlock.Builder) {
+
+        }
+
+        data class Required(
+            override val definition: VariableDefinition,
+            override val type: TypeName
+        ) : VariableType() {
+            override fun generateProperty(): PropertySpec {
+                return PropertySpec.builder(definition.name, type)
+                    .initializer(definition.name)
+                    .build()
+            }
+
+            override fun generateSetterFunction(parentObjectName: ClassName): FunSpec {
+                throw UnsupportedOperationException("Required Variable(${definition.name}) does not need setter")
+            }
+        }
+
+        data class NonNullOptional(
+            override val definition: VariableDefinition,
+            override val type: TypeName
+        ) : VariableType() {
+
+        }
+
+        data class Optional(
+            override val definition: VariableDefinition,
+            override val type: TypeName
+        ) : VariableType() {
+
+        }
+
+        companion object {
+            fun classify(variable: VariableDefinition, typeMapper: KgqlCustomTypeMapper): VariableType {
+                val type = typeMapper.get(variable.type)
+                return if (!type.isNullable && variable.defaultValue == null) {
+                    // required and non-null
+                    Required(variable, type)
+                } else if (!type.isNullable) {
+                    // non-null, but optional
+                    NonNullOptional(variable, type)
+                } else {
+                    // optional
+                    Optional(variable, type)
+                }
+            }
+        }
+    }
+}
diff --git a/kgql-core/src/commonMain/kotlin/com/codingfeline/kgql/core/internal/KgqlValue.kt b/kgql-core/src/commonMain/kotlin/com/codingfeline/kgql/core/internal/KgqlValue.kt
new file mode 100644
index 0000000..3584a4d
--- /dev/null
+++ b/kgql-core/src/commonMain/kotlin/com/codingfeline/kgql/core/internal/KgqlValue.kt
@@ -0,0 +1,9 @@
+package com.codingfeline.kgql.core.internal
+
+/**
+ * Class to express GraphQL's explicit/implicit null
+ */
+sealed class KgqlValue<out T : Any?> {
+    data class Some<out T : Any?>(val value: T) : KgqlValue<T>()
+    object None : KgqlValue<Nothing>()
+}
diff --git a/kgql-core/src/commonMain/kotlin/com/codingfeline/kgql/core/internal/Utilities.kt b/kgql-core/src/commonMain/kotlin/com/codingfeline/kgql/core/internal/Utilities.kt
new file mode 100644
index 0000000..21bb5ba
--- /dev/null
+++ b/kgql-core/src/commonMain/kotlin/com/codingfeline/kgql/core/internal/Utilities.kt
@@ -0,0 +1,3 @@
+package com.codingfeline.kgql.core.internal
+
+fun <T> isEnumSubClass(value: T?): Boolean = value is Enum<*>