diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/descriptors/NodeDescriptor.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/descriptors/NodeDescriptor.kt
index 2d7fa6be..bf09cf70 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/descriptors/NodeDescriptor.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/descriptors/NodeDescriptor.kt
@@ -22,6 +22,7 @@
 package hep.dataforge.descriptors
 
 import hep.dataforge.meta.*
+import hep.dataforge.names.NameToken
 import hep.dataforge.names.toName
 
 /**
@@ -39,6 +40,14 @@ class NodeDescriptor(override val config: Config) : Specification {
      */
     var name: String by string { error("Anonymous descriptors are not allowed") }
 
+
+    /**
+     * The default for this node. Null if there is no default.
+     *
+     * @return
+     */
+    var default: Meta? by node()
+
     /**
      * True if multiple children with this nodes name are allowed. Anonymous
      * nodes are always single
@@ -52,7 +61,7 @@ class NodeDescriptor(override val config: Config) : Specification {
      *
      * @return
      */
-    var required: Boolean by boolean(false)
+    var required: Boolean by boolean { default == null }
 
     /**
      * The node description
@@ -78,6 +87,18 @@ class NodeDescriptor(override val config: Config) : Specification {
             name to ValueDescriptor.wrap(node.node ?: error("Value descriptor must be a node"))
         }
 
+    fun value(name: String, descriptor: ValueDescriptor) {
+        val token = NameToken("value", name)
+        config[token] = descriptor.config
+    }
+
+    /**
+     * Add a value descriptor using block for
+     */
+    fun value(name: String, block: ValueDescriptor.() -> Unit) {
+        value(name, ValueDescriptor.build { this.name = name }.apply(block))
+    }
+
     /**
      * The map of children node descriptors
      */
@@ -87,43 +108,15 @@ class NodeDescriptor(override val config: Config) : Specification {
         }
 
 
-    /**
-     * Check if this node has default
-     *
-     * @return
-     */
-    fun hasDefault(): Boolean {
-        return meta.hasMeta("default")
+    fun node(name: String, descriptor: NodeDescriptor) {
+        val token = NameToken("node", name)
+        config[token] = descriptor.config
     }
 
-    /**
-     * The default meta for this node (could be multiple). Null if not defined
-     *
-     * @return
-     */
-    val default: List<Meta> by nodeList(def = emptyList())
-
-    /**
-     * Identify if this descriptor has child value descriptor with default
-     *
-     * @param name
-     * @return
-     */
-    fun hasDefaultForValue(name: String): Boolean {
-        return getValueDescriptor(name)?.hasDefault() ?: false
+    fun node(name: String, block: NodeDescriptor.() -> Unit) {
+        node(name, NodeDescriptor.build { this.name = name }.apply(block))
     }
 
-    /**
-     * The key of the value which is used to display this node in case it is
-     * multiple. By default, the key is empty which means that node index is
-     * used.
-     *
-     * @return
-     */
-    val key: String by stringValue(def = "")
-
-
-    fun builder(): DescriptorBuilder = DescriptorBuilder(this.name, Configuration(this.meta))
 
     //override val descriptor: NodeDescriptor =  empty("descriptor")
 
@@ -131,8 +124,5 @@ class NodeDescriptor(override val config: Config) : Specification {
 
         override fun wrap(config: Config): NodeDescriptor = NodeDescriptor(config)
 
-        fun empty(nodeName: String): NodeDescriptor {
-            return NodeDescriptor(Meta.buildEmpty(nodeName))
-        }
     }
 }
diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/descriptors/ValueDescriptor.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/descriptors/ValueDescriptor.kt
index 3416b55b..7f066e99 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/descriptors/ValueDescriptor.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/descriptors/ValueDescriptor.kt
@@ -17,7 +17,10 @@
 package hep.dataforge.descriptors
 
 import hep.dataforge.meta.*
-import hep.dataforge.values.*
+import hep.dataforge.values.False
+import hep.dataforge.values.True
+import hep.dataforge.values.Value
+import hep.dataforge.values.ValueType
 
 /**
  * A descriptor for meta value
@@ -35,6 +38,10 @@ class ValueDescriptor(override val config: Config) : Specification {
      */
     var default: Value? by value()
 
+    fun default(v: Any) {
+        this.default = Value.of(v)
+    }
+
     /**
      * True if multiple values with this name are allowed.
      *
@@ -72,6 +79,10 @@ class ValueDescriptor(override val config: Config) : Specification {
         it?.list?.map { v -> ValueType.valueOf(v.string) } ?: emptyList()
     }
 
+    fun type(vararg t: ValueType) {
+        this.type = listOf(*t)
+    }
+
     var tags: List<String> by value().map { value ->
         value?.list?.map { it.string } ?: emptyList()
     }
@@ -103,10 +114,24 @@ class ValueDescriptor(override val config: Config) : Specification {
         }
     }
 
+    /**
+     * Allow given list of value and forbid others
+     */
+    fun allow(vararg v: Any) {
+        this.allowedValues = v.map { Value.of(it) }
+    }
+
     companion object : SpecificationCompanion<ValueDescriptor> {
 
         override fun wrap(config: Config): ValueDescriptor = ValueDescriptor(config)
 
+        inline fun <reified E : Enum<E>> enum(name: String) =
+            ValueDescriptor.build {
+                this.name = name
+                type(ValueType.STRING)
+                this.allowedValues = enumValues<E>().map { Value.of(it.name) }
+            }
+
 //        /**
 //         * Build a value descriptor from annotation
 //         */
diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/descriptors/annotations.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/descriptors/annotations.kt
index 25349ea7..d65a0e79 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/descriptors/annotations.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/descriptors/annotations.kt
@@ -23,14 +23,14 @@ import kotlin.reflect.KClass
 @MustBeDocumented
 annotation class ValueDef(
         val key: String,
-        val type: Array<ValueType> = [ValueType.STRING],
+        val type: Array<ValueType> = arrayOf(ValueType.STRING),
         val multiple: Boolean = false,
         val def: String = "",
         val info: String = "",
         val required: Boolean = true,
-        val allowed: Array<String> = [],
+        val allowed: Array<String> = emptyArray(),
         val enumeration: KClass<*> = Any::class,
-        val tags: Array<String> = []
+        val tags: Array<String> = emptyArray()
 )
 
 @MustBeDocumented
@@ -39,11 +39,11 @@ annotation class NodeDef(
         val info: String = "",
         val multiple: Boolean = false,
         val required: Boolean = false,
-        val tags: Array<String> = [],
+        val tags: Array<String> = emptyArray(),
         /**
          * A list of child value descriptors
          */
-        val values: Array<ValueDef> = [],
+        val values: Array<ValueDef> = emptyArray(),
         /**
          * A target class for this node to describe
          * @return
@@ -135,11 +135,11 @@ annotation class DescriptorValue(val def: ValueDef)
 @MustBeDocumented
 annotation class ValueProperty(
         val name: String = "",
-        val type: Array<ValueType> = [ValueType.STRING],
+        val type: Array<ValueType> = arrayOf(ValueType.STRING),
         val multiple: Boolean = false,
         val def: String = "",
         val enumeration: KClass<*> = Any::class,
-        val tags: Array<String> = []
+        val tags: Array<String> = emptyArray()
 )
 
 
diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/ConfigDelegates.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/ConfigDelegates.kt
index 8e717948..9a5f15cb 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/ConfigDelegates.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/ConfigDelegates.kt
@@ -11,45 +11,45 @@ import kotlin.jvm.JvmName
  * A property delegate that uses custom key
  */
 fun Configurable.value(default: Any = Null, key: String? = null) =
-    ValueConfigDelegate(config, key, Value.of(default))
+    MutableValueDelegate(config, key, Value.of(default))
 
 fun Configurable.string(default: String? = null, key: String? = null) =
-    StringConfigDelegate(config, key, default)
+    MutableStringDelegate(config, key, default)
 
 fun Configurable.boolean(default: Boolean? = null, key: String? = null) =
-    BooleanConfigDelegate(config, key, default)
+    MutableBooleanDelegate(config, key, default)
 
 fun Configurable.number(default: Number? = null, key: String? = null) =
-    NumberConfigDelegate(config, key, default)
+    MutableNumberDelegate(config, key, default)
 
-fun Configurable.child(key: String? = null) = MetaNodeDelegate(config, key)
+fun Configurable.node(key: String? = null) = MutableNodeDelegate(config, key)
 
 //fun <T : Configurable> Configurable.spec(spec: Specification<T>, key: String? = null) = ChildConfigDelegate<T>(key) { spec.wrap(this) }
 
 @JvmName("safeString")
 fun Configurable.string(default: String, key: String? = null) =
-    SafeStringConfigDelegate(config, key) { default }
+    MutableSafeStringDelegate(config, key) { default }
 
 @JvmName("safeBoolean")
 fun Configurable.boolean(default: Boolean, key: String? = null) =
-    SafeBooleanConfigDelegate(config, key) { default }
+    MutableSafeBooleanDelegate(config, key) { default }
 
 @JvmName("safeNumber")
 fun Configurable.number(default: Number, key: String? = null) =
-    SafeNumberConfigDelegate(config, key) { default }
+    MutableSafeNumberDelegate(config, key) { default }
 
 @JvmName("safeString")
 fun Configurable.string(key: String? = null, default: () -> String) =
-    SafeStringConfigDelegate(config, key, default)
+    MutableSafeStringDelegate(config, key, default)
 
 @JvmName("safeBoolean")
 fun Configurable.boolean(key: String? = null, default: () -> Boolean) =
-    SafeBooleanConfigDelegate(config, key, default)
+    MutableSafeBooleanDelegate(config, key, default)
 
 @JvmName("safeNumber")
 fun Configurable.number(key: String? = null, default: () -> Number) =
-    SafeNumberConfigDelegate(config, key, default)
+    MutableSafeNumberDelegate(config, key, default)
 
 
 inline fun <reified E : Enum<E>> Configurable.enum(default: E, key: String? = null) =
-    SafeEnumvConfigDelegate(config, key, default) { enumValueOf(it) }
\ No newline at end of file
+    MutableSafeEnumvDelegate(config, key, default) { enumValueOf(it) }
\ No newline at end of file
diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Delegates.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Delegates.kt
index 5a7e845d..119b78b0 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Delegates.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Delegates.kt
@@ -164,23 +164,23 @@ inline fun <reified E : Enum<E>> Meta.enum(default: E, key: String? = null) =
     SafeEnumDelegate(this, key, default) { enumValueOf(it) }
 
 
-/* Config delegates */
+/* Read-write delegates */
 
-class ValueConfigDelegate<M : MutableMeta<M>>(
-    val config: M,
+class MutableValueDelegate<M : MutableMeta<M>>(
+    val meta: M,
     private val key: String? = null,
     private val default: Value? = null
 ) : ReadWriteProperty<Any?, Value?> {
     override fun getValue(thisRef: Any?, property: KProperty<*>): Value? {
-        return config[key ?: property.name]?.value ?: default
+        return meta[key ?: property.name]?.value ?: default
     }
 
     override fun setValue(thisRef: Any?, property: KProperty<*>, value: Value?) {
         val name = key ?: property.name
         if (value == null) {
-            config.remove(name)
+            meta.remove(name)
         } else {
-            config.setValue(name, value)
+            meta.setValue(name, value)
         }
     }
 
@@ -188,59 +188,59 @@ class ValueConfigDelegate<M : MutableMeta<M>>(
         ReadWriteDelegateWrapper(this, reader, writer)
 }
 
-class StringConfigDelegate<M : MutableMeta<M>>(
-    val config: M,
+class MutableStringDelegate<M : MutableMeta<M>>(
+    val meta: M,
     private val key: String? = null,
     private val default: String? = null
 ) : ReadWriteProperty<Any?, String?> {
     override fun getValue(thisRef: Any?, property: KProperty<*>): String? {
-        return config[key ?: property.name]?.string ?: default
+        return meta[key ?: property.name]?.string ?: default
     }
 
     override fun setValue(thisRef: Any?, property: KProperty<*>, value: String?) {
         val name = key ?: property.name
         if (value == null) {
-            config.remove(name)
+            meta.remove(name)
         } else {
-            config.setValue(name, value.asValue())
+            meta.setValue(name, value.asValue())
         }
     }
 }
 
-class BooleanConfigDelegate<M : MutableMeta<M>>(
-    val config: M,
+class MutableBooleanDelegate<M : MutableMeta<M>>(
+    val meta: M,
     private val key: String? = null,
     private val default: Boolean? = null
 ) : ReadWriteProperty<Any?, Boolean?> {
     override fun getValue(thisRef: Any?, property: KProperty<*>): Boolean? {
-        return config[key ?: property.name]?.boolean ?: default
+        return meta[key ?: property.name]?.boolean ?: default
     }
 
     override fun setValue(thisRef: Any?, property: KProperty<*>, value: Boolean?) {
         val name = key ?: property.name
         if (value == null) {
-            config.remove(name)
+            meta.remove(name)
         } else {
-            config.setValue(name, value.asValue())
+            meta.setValue(name, value.asValue())
         }
     }
 }
 
-class NumberConfigDelegate<M : MutableMeta<M>>(
-    val config: M,
+class MutableNumberDelegate<M : MutableMeta<M>>(
+    val meta: M,
     private val key: String? = null,
     private val default: Number? = null
 ) : ReadWriteProperty<Any?, Number?> {
     override fun getValue(thisRef: Any?, property: KProperty<*>): Number? {
-        return config[key ?: property.name]?.number ?: default
+        return meta[key ?: property.name]?.number ?: default
     }
 
     override fun setValue(thisRef: Any?, property: KProperty<*>, value: Number?) {
         val name = key ?: property.name
         if (value == null) {
-            config.remove(name)
+            meta.remove(name)
         } else {
-            config.setValue(name, value.asValue())
+            meta.setValue(name, value.asValue())
         }
     }
 
@@ -252,8 +252,8 @@ class NumberConfigDelegate<M : MutableMeta<M>>(
 
 //Delegates with non-null values
 
-class SafeStringConfigDelegate<M : MutableMeta<M>>(
-    val config: M,
+class MutableSafeStringDelegate<M : MutableMeta<M>>(
+    val meta: M,
     private val key: String? = null,
     default: () -> String
 ) : ReadWriteProperty<Any?, String> {
@@ -261,16 +261,16 @@ class SafeStringConfigDelegate<M : MutableMeta<M>>(
     private val default: String by lazy(default)
 
     override fun getValue(thisRef: Any?, property: KProperty<*>): String {
-        return config[key ?: property.name]?.string ?: default
+        return meta[key ?: property.name]?.string ?: default
     }
 
     override fun setValue(thisRef: Any?, property: KProperty<*>, value: String) {
-        config.setValue(key ?: property.name, value.asValue())
+        meta.setValue(key ?: property.name, value.asValue())
     }
 }
 
-class SafeBooleanConfigDelegate<M : MutableMeta<M>>(
-    val config: M,
+class MutableSafeBooleanDelegate<M : MutableMeta<M>>(
+    val meta: M,
     private val key: String? = null,
     default: () -> Boolean
 ) : ReadWriteProperty<Any?, Boolean> {
@@ -278,16 +278,16 @@ class SafeBooleanConfigDelegate<M : MutableMeta<M>>(
     private val default: Boolean by lazy(default)
 
     override fun getValue(thisRef: Any?, property: KProperty<*>): Boolean {
-        return config[key ?: property.name]?.boolean ?: default
+        return meta[key ?: property.name]?.boolean ?: default
     }
 
     override fun setValue(thisRef: Any?, property: KProperty<*>, value: Boolean) {
-        config.setValue(key ?: property.name, value.asValue())
+        meta.setValue(key ?: property.name, value.asValue())
     }
 }
 
-class SafeNumberConfigDelegate<M : MutableMeta<M>>(
-    val config: M,
+class MutableSafeNumberDelegate<M : MutableMeta<M>>(
+    val meta: M,
     private val key: String? = null,
     default: () -> Number
 ) : ReadWriteProperty<Any?, Number> {
@@ -295,11 +295,11 @@ class SafeNumberConfigDelegate<M : MutableMeta<M>>(
     private val default: Number by lazy(default)
 
     override fun getValue(thisRef: Any?, property: KProperty<*>): Number {
-        return config[key ?: property.name]?.number ?: default
+        return meta[key ?: property.name]?.number ?: default
     }
 
     override fun setValue(thisRef: Any?, property: KProperty<*>, value: Number) {
-        config.setValue(key ?: property.name, value.asValue())
+        meta.setValue(key ?: property.name, value.asValue())
     }
 
     val double get() = ReadWriteDelegateWrapper(this, reader = { it.toDouble() }, writer = { it })
@@ -308,48 +308,48 @@ class SafeNumberConfigDelegate<M : MutableMeta<M>>(
     val long get() = ReadWriteDelegateWrapper(this, reader = { it.toLong() }, writer = { it })
 }
 
-class SafeEnumvConfigDelegate<M : MutableMeta<M>, E : Enum<E>>(
-    val config: M,
+class MutableSafeEnumvDelegate<M : MutableMeta<M>, E : Enum<E>>(
+    val meta: M,
     private val key: String? = null,
     private val default: E,
     private val resolver: (String) -> E
 ) : ReadWriteProperty<Any?, E> {
     override fun getValue(thisRef: Any?, property: KProperty<*>): E {
-        return (config[key ?: property.name]?.string)?.let { resolver(it) } ?: default
+        return (meta[key ?: property.name]?.string)?.let { resolver(it) } ?: default
     }
 
     override fun setValue(thisRef: Any?, property: KProperty<*>, value: E) {
-        config.setValue(key ?: property.name, value.name.asValue())
+        meta.setValue(key ?: property.name, value.name.asValue())
     }
 }
 
 //Child node delegate
 
-class MetaNodeDelegate<M : MutableMetaNode<M>>(
-    val config: M,
+class MutableNodeDelegate<M : MutableMetaNode<M>>(
+    val meta: M,
     private val key: String? = null
-) : ReadWriteProperty<Any?, Meta> {
-    override fun getValue(thisRef: Any?, property: KProperty<*>): Meta {
-        return config[key ?: property.name]?.node ?: EmptyMeta
+) : ReadWriteProperty<Any?, Meta?> {
+    override fun getValue(thisRef: Any?, property: KProperty<*>): Meta? {
+        return meta[key ?: property.name]?.node
     }
 
-    override fun setValue(thisRef: Any?, property: KProperty<*>, value: Meta) {
-        config[key ?: property.name] = value
+    override fun setValue(thisRef: Any?, property: KProperty<*>, value: Meta?) {
+        meta[key ?: property.name] = value
     }
 }
 
-class ChildConfigDelegate<M : MutableMetaNode<M>, T : Configurable>(
-    val config: M,
+class MutableMorphDelegate<M : MutableMetaNode<M>, T : Configurable>(
+    val meta: M,
     private val key: String? = null,
     private val converter: (Meta) -> T
 ) :
     ReadWriteProperty<Any?, T> {
     override fun getValue(thisRef: Any?, property: KProperty<*>): T {
-        return converter(config[key ?: property.name]?.node ?: EmptyMeta)
+        return converter(meta[key ?: property.name]?.node ?: EmptyMeta)
     }
 
     override fun setValue(thisRef: Any?, property: KProperty<*>, value: T) {
-        config[key ?: property.name] = value.config
+        meta[key ?: property.name] = value.config
     }
 }
 
@@ -374,45 +374,43 @@ class ReadWriteDelegateWrapper<T, R>(
  * A property delegate that uses custom key
  */
 fun <M : MutableMeta<M>> M.value(default: Value = Null, key: String? = null) =
-    ValueConfigDelegate(this, key, default)
+    MutableValueDelegate(this, key, default)
 
 fun <M : MutableMeta<M>> M.string(default: String? = null, key: String? = null) =
-    StringConfigDelegate(this, key, default)
+    MutableStringDelegate(this, key, default)
 
 fun <M : MutableMeta<M>> M.boolean(default: Boolean? = null, key: String? = null) =
-    BooleanConfigDelegate(this, key, default)
+    MutableBooleanDelegate(this, key, default)
 
 fun <M : MutableMeta<M>> M.number(default: Number? = null, key: String? = null) =
-    NumberConfigDelegate(this, key, default)
+    MutableNumberDelegate(this, key, default)
 
-fun <M : MutableMetaNode<M>> M.child(key: String? = null) = MetaNodeDelegate(this, key)
-
-//fun <T : Configurable> Configurable.spec(spec: Specification<T>, key: String? = null) = ChildConfigDelegate<T>(key) { spec.wrap(this) }
+fun <M : MutableMetaNode<M>> M.node(key: String? = null) = MutableNodeDelegate(this, key)
 
 @JvmName("safeString")
 fun <M : MutableMeta<M>> M.string(default: String, key: String? = null) =
-    SafeStringConfigDelegate(this, key) { default }
+    MutableSafeStringDelegate(this, key) { default }
 
 @JvmName("safeBoolean")
 fun <M : MutableMeta<M>> M.boolean(default: Boolean, key: String? = null) =
-    SafeBooleanConfigDelegate(this, key) { default }
+    MutableSafeBooleanDelegate(this, key) { default }
 
 @JvmName("safeNumber")
 fun <M : MutableMeta<M>> M.number(default: Number, key: String? = null) =
-    SafeNumberConfigDelegate(this, key) { default }
+    MutableSafeNumberDelegate(this, key) { default }
 
 @JvmName("safeString")
 fun <M : MutableMeta<M>> M.string(key: String? = null, default: () -> String) =
-    SafeStringConfigDelegate(this, key, default)
+    MutableSafeStringDelegate(this, key, default)
 
 @JvmName("safeBoolean")
 fun <M : MutableMeta<M>> M.boolean(key: String? = null, default: () -> Boolean) =
-    SafeBooleanConfigDelegate(this, key, default)
+    MutableSafeBooleanDelegate(this, key, default)
 
 @JvmName("safeNumber")
 fun <M : MutableMeta<M>> M.number(key: String? = null, default: () -> Number) =
-    SafeNumberConfigDelegate(this, key, default)
+    MutableSafeNumberDelegate(this, key, default)
 
 
 inline fun <M : MutableMeta<M>, reified E : Enum<E>> M.enum(default: E, key: String? = null) =
-    SafeEnumvConfigDelegate(this, key, default) { enumValueOf(it) }
+    MutableSafeEnumvDelegate(this, key, default) { enumValueOf(it) }
diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/ExtraMetaDelegates.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/ExtraMetaDelegates.kt
index d0eaa54e..6e24c6d0 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/ExtraMetaDelegates.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/ExtraMetaDelegates.kt
@@ -33,4 +33,4 @@ fun Configurable.stringList(vararg default: String = emptyArray(), key: String?
 fun <T : Metoid> Metoid.child(key: String? = null, converter: (Meta) -> T) = ChildDelegate(meta, key, converter)
 
 fun <T : Configurable> Configurable.child(key: String? = null, converter: (Meta) -> T) =
-    ChildConfigDelegate(config, key, converter)
+    MutableMorphDelegate(config, key, converter)
diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/MutableMeta.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/MutableMeta.kt
index 2e7f452f..1d26b2b7 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/MutableMeta.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/MutableMeta.kt
@@ -125,6 +125,8 @@ operator fun <M : MutableMetaNode<M>> M.set(name: Name, value: Any?) {
     }
 }
 
+operator fun <M : MutableMetaNode<M>> M.set(name: NameToken, value: Any?) = set(Name(key), value)
+
 operator fun <M : MutableMetaNode<M>> M.set(key: String, value: Any?) = set(key.toName(), value)
 
 /**
diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Specification.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Specification.kt
index f1e2beaf..a578b119 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Specification.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Specification.kt
@@ -59,4 +59,4 @@ fun <M : MutableMetaNode<M>, C : Specification> Specification.spec(
     spec: SpecificationCompanion<C>,
     key: String? = null
 ) =
-    ChildConfigDelegate(config, key) { spec.wrap(config) }
\ No newline at end of file
+    MutableMorphDelegate(config, key) { spec.wrap(config) }
\ No newline at end of file
diff --git a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Styled.kt b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Styled.kt
index ba802f5f..dcc36a5a 100644
--- a/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Styled.kt
+++ b/dataforge-meta/src/commonMain/kotlin/hep/dataforge/meta/Styled.kt
@@ -48,7 +48,7 @@ class Styled(val base: Meta, val style: Config = Config().empty()) : MutableMeta
     }
 }
 
-fun Styled.configure(meta: Meta) = apply { style.update(style) }
+fun Styled.configure(meta: Meta) = apply { style.update(meta) }
 
 fun Meta.withStyle(style: Meta = EmptyMeta) = if (this is Styled) {
     this.apply { this.configure(style) }
diff --git a/dataforge-meta/src/jsMain/kotlin/hep/dataforge/meta/jsMeta.kt b/dataforge-meta/src/jsMain/kotlin/hep/dataforge/meta/jsMeta.kt
index 9002fec1..0858f67a 100644
--- a/dataforge-meta/src/jsMain/kotlin/hep/dataforge/meta/jsMeta.kt
+++ b/dataforge-meta/src/jsMain/kotlin/hep/dataforge/meta/jsMeta.kt
@@ -1,8 +1,6 @@
 package hep.dataforge.meta
 
 
-
-
 fun Meta.toDynamic(): dynamic {
     fun MetaItem<*>.toDynamic(): dynamic = when (this) {
         is MetaItem.ValueItem -> this.value.value.asDynamic()