diff --git a/controls-constructor/src/commonMain/kotlin/space/kscience/controls/constructor/ConstructorElement.kt b/controls-constructor/src/commonMain/kotlin/space/kscience/controls/constructor/ConstructorElement.kt
index 8073689..4d2f476 100644
--- a/controls-constructor/src/commonMain/kotlin/space/kscience/controls/constructor/ConstructorElement.kt
+++ b/controls-constructor/src/commonMain/kotlin/space/kscience/controls/constructor/ConstructorElement.kt
@@ -32,7 +32,7 @@ public class StateConstructorElement<T>(
     public val state: DeviceState<T>,
 ) : ConstructorElement
 
-public class ConnectionConstrucorElement(
+public class ConnectionConstructorElement(
     public val reads: Collection<DeviceState<*>>,
     public val writes: Collection<DeviceState<*>>,
 ) : ConstructorElement
@@ -58,7 +58,7 @@ public interface StateContainer : ContextAware, CoroutineScope {
         reads: Collection<DeviceState<*>> = emptySet(),
         onChange: suspend (T) -> Unit,
     ): Job = valueFlow.onEach(onChange).launchIn(this@StateContainer).also {
-        registerElement(ConnectionConstrucorElement(reads + this, writes))
+        registerElement(ConnectionConstructorElement(reads + this, writes))
     }
 
     public fun <T> DeviceState<T>.onChange(
@@ -72,7 +72,7 @@ public interface StateContainer : ContextAware, CoroutineScope {
             onChange(pair.first, pair.second)
         }
     }.launchIn(this@StateContainer).also {
-        registerElement(ConnectionConstrucorElement(reads + this, writes))
+        registerElement(ConnectionConstructorElement(reads + this, writes))
     }
 }
 
@@ -164,7 +164,7 @@ public fun <T1, T2, R> StateContainer.combineState(
  * On resulting [Job] cancel the binding is unregistered
  */
 public fun <T> StateContainer.bind(sourceState: DeviceState<T>, targetState: MutableDeviceState<T>): Job {
-    val descriptor = ConnectionConstrucorElement(setOf(sourceState), setOf(targetState))
+    val descriptor = ConnectionConstructorElement(setOf(sourceState), setOf(targetState))
     registerElement(descriptor)
     return sourceState.valueFlow.onEach {
         targetState.value = it
@@ -186,7 +186,7 @@ public fun <T, R> StateContainer.transformTo(
     targetState: MutableDeviceState<R>,
     transformation: suspend (T) -> R,
 ): Job {
-    val descriptor = ConnectionConstrucorElement(setOf(sourceState), setOf(targetState))
+    val descriptor = ConnectionConstructorElement(setOf(sourceState), setOf(targetState))
     registerElement(descriptor)
     return sourceState.valueFlow.onEach {
         targetState.value = transformation(it)
@@ -208,7 +208,7 @@ public fun <T1, T2, R> StateContainer.combineTo(
     targetState: MutableDeviceState<R>,
     transformation: suspend (T1, T2) -> R,
 ): Job {
-    val descriptor = ConnectionConstrucorElement(setOf(sourceState1, sourceState2), setOf(targetState))
+    val descriptor = ConnectionConstructorElement(setOf(sourceState1, sourceState2), setOf(targetState))
     registerElement(descriptor)
     return kotlinx.coroutines.flow.combine(sourceState1.valueFlow, sourceState2.valueFlow, transformation).onEach {
         targetState.value = it
@@ -229,7 +229,7 @@ public inline fun <reified T, R> StateContainer.combineTo(
     targetState: MutableDeviceState<R>,
     noinline transformation: suspend (Array<T>) -> R,
 ): Job {
-    val descriptor = ConnectionConstrucorElement(sourceStates, setOf(targetState))
+    val descriptor = ConnectionConstructorElement(sourceStates, setOf(targetState))
     registerElement(descriptor)
     return kotlinx.coroutines.flow.combine(sourceStates.map { it.valueFlow }, transformation).onEach {
         targetState.value = it
diff --git a/controls-core/src/commonMain/kotlin/space/kscience/controls/api/descriptors.kt b/controls-core/src/commonMain/kotlin/space/kscience/controls/api/descriptors.kt
index f3ffa93..bda25bb 100644
--- a/controls-core/src/commonMain/kotlin/space/kscience/controls/api/descriptors.kt
+++ b/controls-core/src/commonMain/kotlin/space/kscience/controls/api/descriptors.kt
@@ -4,34 +4,109 @@ import kotlinx.serialization.Serializable
 import space.kscience.dataforge.meta.descriptors.MetaDescriptor
 import space.kscience.dataforge.meta.descriptors.MetaDescriptorBuilder
 
-//TODO add proper builders
+//TODO check proper builders
 
 /**
- * A descriptor for property
+ * A descriptor for a property
  */
 @Serializable
 public class PropertyDescriptor(
     public val name: String,
-    public var description: String? = null,
-    public var metaDescriptor: MetaDescriptor = MetaDescriptor(),
-    public var readable: Boolean = true,
-    public var mutable: Boolean = false,
+    public val description: String? = null,
+    public val metaDescriptor: MetaDescriptor = MetaDescriptor(),
+    public val readable: Boolean = true,
+    public val mutable: Boolean = false,
 )
 
-public fun PropertyDescriptor.metaDescriptor(block: MetaDescriptorBuilder.() -> Unit) {
-    metaDescriptor = MetaDescriptor {
-        from(metaDescriptor)
-        block()
+/**
+ * A builder for PropertyDescriptor
+ */
+public class PropertyDescriptorBuilder(public val name: String) {
+    public var description: String? = null
+    public var metaDescriptor: MetaDescriptor = MetaDescriptor()
+    public var readable: Boolean = true
+    public var mutable: Boolean = false
+
+    /**
+     * Configure the metaDescriptor using a block
+     */
+    public fun metaDescriptor(block: MetaDescriptorBuilder.() -> Unit) {
+        metaDescriptor = MetaDescriptor {
+            from(metaDescriptor)
+            block()
+        }
     }
+
+    /**
+     * Build the PropertyDescriptor
+     */
+    public fun build(): PropertyDescriptor = PropertyDescriptor(
+        name = name,
+        description = description,
+        metaDescriptor = metaDescriptor,
+        readable = readable,
+        mutable = mutable
+    )
 }
 
 /**
- * A descriptor for property
+ * Create a PropertyDescriptor using a builder
+ */
+public fun propertyDescriptor(name: String, builder: PropertyDescriptorBuilder.() -> Unit = {}): PropertyDescriptor =
+    PropertyDescriptorBuilder(name).apply(builder).build()
+
+/**
+ * A descriptor for an action
  */
 @Serializable
 public class ActionDescriptor(
     public val name: String,
-    public var description: String? = null,
-    public var inputMetaDescriptor: MetaDescriptor = MetaDescriptor(),
-    public var outputMetaDescriptor: MetaDescriptor = MetaDescriptor()
+    public val description: String? = null,
+    public val inputMetaDescriptor: MetaDescriptor = MetaDescriptor(),
+    public val outputMetaDescriptor: MetaDescriptor = MetaDescriptor(),
 )
+
+/**
+ * A builder for ActionDescriptor
+ */
+public class ActionDescriptorBuilder(public val name: String) {
+    public var description: String? = null
+    public var inputMetaDescriptor: MetaDescriptor = MetaDescriptor()
+    public var outputMetaDescriptor: MetaDescriptor = MetaDescriptor()
+
+    /**
+     * Configure the inputMetaDescriptor using a block
+     */
+    public fun inputMeta(block: MetaDescriptorBuilder.() -> Unit) {
+        inputMetaDescriptor = MetaDescriptor {
+            from(inputMetaDescriptor)
+            block()
+        }
+    }
+
+    /**
+     * Configure the outputMetaDescriptor using a block
+     */
+    public fun outputMeta(block: MetaDescriptorBuilder.() -> Unit) {
+        outputMetaDescriptor = MetaDescriptor {
+            from(outputMetaDescriptor)
+            block()
+        }
+    }
+
+    /**
+     * Build the ActionDescriptor
+     */
+    public fun build(): ActionDescriptor = ActionDescriptor(
+        name = name,
+        description = description,
+        inputMetaDescriptor = inputMetaDescriptor,
+        outputMetaDescriptor = outputMetaDescriptor
+    )
+}
+
+/**
+ * Create an ActionDescriptor using a builder
+ */
+public fun actionDescriptor(name: String, builder: ActionDescriptorBuilder.() -> Unit = {}): ActionDescriptor =
+    ActionDescriptorBuilder(name).apply(builder).build()
diff --git a/controls-core/src/commonMain/kotlin/space/kscience/controls/spec/CompositeControlComponents.kt b/controls-core/src/commonMain/kotlin/space/kscience/controls/spec/CompositeControlComponents.kt
new file mode 100644
index 0000000..259238a
--- /dev/null
+++ b/controls-core/src/commonMain/kotlin/space/kscience/controls/spec/CompositeControlComponents.kt
@@ -0,0 +1,809 @@
+package space.kscience.controls.spec
+
+import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.CoroutineName
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.cancelAndJoin
+import kotlinx.coroutines.channels.BufferOverflow
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.flow.SharedFlow
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
+import kotlinx.coroutines.withTimeoutOrNull
+import space.kscience.controls.api.*
+import space.kscience.dataforge.context.Context
+import space.kscience.dataforge.context.error
+import space.kscience.dataforge.context.logger
+import space.kscience.dataforge.meta.Meta
+import space.kscience.dataforge.meta.MetaConverter
+import space.kscience.dataforge.meta.MutableMeta
+import space.kscience.dataforge.names.Name
+import space.kscience.dataforge.names.asName
+import space.kscience.dataforge.names.parseAsName
+import space.kscience.dataforge.names.plus
+import kotlin.properties.PropertyDelegateProvider
+import kotlin.properties.ReadOnlyProperty
+import kotlin.reflect.KProperty
+import kotlin.time.Duration
+import kotlinx.coroutines.flow.filter
+import kotlinx.coroutines.flow.filterIsInstance
+import kotlinx.coroutines.flow.onEach
+import kotlinx.coroutines.flow.launchIn
+import space.kscience.dataforge.context.AbstractPlugin
+import space.kscience.dataforge.context.ContextAware
+import space.kscience.dataforge.context.ContextBuilder
+import space.kscience.dataforge.context.PluginFactory
+import space.kscience.dataforge.context.PluginTag
+
+/**
+ * Defines how child device lifecycle should be managed.
+ */
+public enum class LifecycleMode {
+    /**
+     * Device starts and stops with parent
+     */
+    LINKED,
+
+    /**
+     * Device is started and stopped independently
+     */
+    INDEPENDENT,
+
+    /**
+     * Device is created but starts only when explicitly requested
+     */
+    LAZY
+}
+
+public sealed class DeviceChangeEvent {
+    public abstract val deviceName: Name
+
+    public data class Added(override val deviceName: Name, val device: Device) : DeviceChangeEvent()
+    public data class Removed(override val deviceName: Name) : DeviceChangeEvent()
+}
+
+public interface ComponentRegistry : ContextAware {
+    public fun <D: ConfigurableCompositeControlComponent<*>> getSpec(name: Name): CompositeControlComponentSpec<D>?
+}
+
+public class ComponentRegistryManager : AbstractPlugin(), ComponentRegistry {
+    private val specs = mutableMapOf<Name, CompositeControlComponentSpec<*>>()
+
+    override val tag: PluginTag = Companion.tag
+
+    override fun <D : ConfigurableCompositeControlComponent<*>> getSpec(name: Name): CompositeControlComponentSpec<D>? {
+        try {
+            return specs[name] as? CompositeControlComponentSpec<D>
+        } catch (e: ClassCastException) {
+            logger.error(e) { "Failed to get spec $name" }
+        }
+        return null
+    }
+
+    public fun registerSpec(spec: CompositeControlComponentSpec<*>) {
+        specs[(spec as DevicePropertySpec<*, *>).name.asName()] = spec
+    }
+
+    public companion object : PluginFactory<ComponentRegistryManager> {
+        override val tag: PluginTag = PluginTag("controls.spechub", group = PluginTag.DATAFORGE_GROUP)
+
+        override fun build(context: Context, meta: Meta): ComponentRegistryManager = ComponentRegistryManager()
+
+    }
+}
+public val Context.componentRegistry: ComponentRegistry? get() = plugins[ComponentRegistryManager]
+
+public fun ContextBuilder.withSpecHub() {
+    plugin(ComponentRegistryManager)
+}
+
+/**
+ * Builder for [DeviceLifecycleConfig].
+ */
+public class DeviceLifecycleConfigBuilder {
+    public var lifecycleMode: LifecycleMode = LifecycleMode.LINKED
+    public var messageBuffer: Int = 1000
+    public var startDelay: Duration = Duration.ZERO
+    public var startTimeout: Duration? = null
+    public var stopTimeout: Duration? = null
+    public var coroutineScope: CoroutineScope? = null
+    public var dispatcher: CoroutineDispatcher? = null
+    public var onError: ChildDeviceErrorHandler = ChildDeviceErrorHandler.RESTART
+
+    public fun build(): DeviceLifecycleConfig = DeviceLifecycleConfig(
+        lifecycleMode, messageBuffer, startDelay, startTimeout, stopTimeout, coroutineScope, dispatcher, onError
+    )
+}
+
+public fun DeviceLifecycleConfigBuilder.linked() {
+    lifecycleMode = LifecycleMode.LINKED
+}
+
+public fun DeviceLifecycleConfigBuilder.independent() {
+    lifecycleMode = LifecycleMode.INDEPENDENT
+}
+
+public fun DeviceLifecycleConfigBuilder.lazy() {
+    lifecycleMode = LifecycleMode.LAZY
+}
+
+public fun DeviceLifecycleConfigBuilder.restartOnError() {
+    onError = ChildDeviceErrorHandler.RESTART
+}
+
+public fun DeviceLifecycleConfigBuilder.propagateError() {
+    onError = ChildDeviceErrorHandler.PROPAGATE
+}
+
+public fun DeviceLifecycleConfigBuilder.withCustomTimeout(timeout: Duration) {
+    startTimeout = timeout
+    stopTimeout = timeout
+}
+
+@OptIn(InternalDeviceAPI::class)
+public abstract class CompositeControlComponentSpec<D : Device>() : CompositeDeviceSpec<D> {
+
+    private val _properties = hashMapOf<String, DevicePropertySpec<D, *>>(
+        DeviceMetaPropertySpec.name to DeviceMetaPropertySpec
+    )
+
+    override val properties: Map<String, DevicePropertySpec<D, *>> get() = _properties
+
+    private val _actions = hashMapOf<String, DeviceActionSpec<D, *, *>>()
+
+    override val actions: Map<String, DeviceActionSpec<D, *, *>> get() = _actions
+
+    private val _childSpecs = mutableMapOf<String, ChildComponentConfig<*>>()
+
+    override val childSpecs: Map<String, ChildComponentConfig<*>> get() = _childSpecs
+
+    public fun <CDS: CompositeControlComponentSpec<CD>, CD: ConfigurableCompositeControlComponent<CD>> childSpec(
+        deviceName: String? = null,
+        specName: Name? = null,
+        metaBuilder: (MutableMeta.() -> Unit)? = null,
+        configBuilder: DeviceLifecycleConfigBuilder.() -> Unit = {},
+    ): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, CompositeControlComponentSpec<CD>>> =
+        PropertyDelegateProvider { thisRef, property ->
+            ReadOnlyProperty { _, _ ->
+                val childSpecName = specName ?: property.name.asName()
+                val nameForDevice = deviceName?.asName() ?: property.name.asName()
+                val config = DeviceLifecycleConfigBuilder().apply(configBuilder).build()
+                val meta = metaBuilder?.let { Meta(it) }
+                val spec = (thisRef as ConfigurableCompositeControlComponent<*>).context.componentRegistry?.getSpec<CD>(childSpecName) ?: error("Spec with name '$specName' is not found")
+                val childComponentConfig = object : ChildComponentConfig<CD>{
+                    override val spec: CompositeControlComponentSpec<CD> = spec
+                    override val config: DeviceLifecycleConfig = config
+                    override val meta: Meta? = meta
+                    override val name: Name = nameForDevice
+                }
+                _childSpecs[property.name] = childComponentConfig
+                childComponentConfig.spec
+            }
+        }
+
+    override fun validate(device: D) {
+        properties.map { it.value.descriptor }.forEach { specProperty ->
+            check(specProperty in device.propertyDescriptors) { "Property ${specProperty.name} not registered in ${device.id}" }
+        }
+        actions.map { it.value.descriptor }.forEach { specAction ->
+            check(specAction in device.actionDescriptors) { "Action ${specAction.name} not registered in ${device.id}" }
+        }
+    }
+
+    override fun <T, P : DevicePropertySpec<D, T>> registerProperty(deviceProperty: P): P {
+        _properties[deviceProperty.name] = deviceProperty
+        return deviceProperty
+    }
+
+    override fun <I, O> registerAction(deviceAction: DeviceActionSpec<D, I, O>): DeviceActionSpec<D, I, O> {
+        _actions[deviceAction.name] = deviceAction
+        return deviceAction
+    }
+
+    override fun createPropertyDescriptorInternal(
+        propertyName: String,
+        converter: MetaConverter<*>,
+        mutable: Boolean,
+        property: KProperty<*>,
+        descriptorBuilder: PropertyDescriptorBuilder.() -> Unit,
+    ): PropertyDescriptor {
+        return propertyDescriptor(propertyName) {
+            this.mutable = mutable
+            converter.descriptor?.let { converterDescriptor ->
+                metaDescriptor {
+                    from(converterDescriptor)
+                }
+            }
+            fromSpec(property)
+            descriptorBuilder()
+        }
+    }
+
+    override fun createActionDescriptor(
+        actionName: String,
+        inputConverter: MetaConverter<*>,
+        outputConverter: MetaConverter<*>,
+        property: KProperty<*>,
+        descriptorBuilder: ActionDescriptorBuilder.() -> Unit,
+    ): ActionDescriptor {
+        return actionDescriptor(actionName) {
+            inputConverter.descriptor?.let { converterDescriptor ->
+                inputMeta {
+                    from(converterDescriptor)
+                }
+            }
+            outputConverter.descriptor?.let { converterDescriptor ->
+                outputMeta {
+                    from(converterDescriptor)
+                }
+            }
+            fromSpec(property)
+            descriptorBuilder()
+        }
+    }
+
+    override fun <T> property(
+        converter: MetaConverter<T>,
+        descriptorBuilder: PropertyDescriptorBuilder.() -> Unit,
+        name: String?,
+        read: suspend D.(propertyName: String) -> T?,
+    ): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, DevicePropertySpec<D, T>>> =
+        PropertyDelegateProvider { _: CompositeControlComponentSpec<D>, property ->
+            val propertyName = name ?: property.name
+            val descriptor = createPropertyDescriptorInternal(
+                propertyName = propertyName,
+                converter = converter,
+                mutable = false,
+                property = property,
+                descriptorBuilder = descriptorBuilder
+            )
+            val deviceProperty = registerProperty(object : DevicePropertySpec<D, T> {
+                override val descriptor = descriptor
+                override val converter = converter
+
+                override suspend fun read(device: D): T? =
+                    withContext(device.coroutineContext) { device.read(propertyName) }
+            })
+            ReadOnlyProperty { _, _ ->
+                deviceProperty
+            }
+        }
+
+
+    override fun <T> mutableProperty(
+        converter: MetaConverter<T>,
+        descriptorBuilder: PropertyDescriptorBuilder.() -> Unit,
+        name: String?,
+        read: suspend D.(propertyName: String) -> T?,
+        write: suspend D.(propertyName: String, value: T) -> Unit
+    ): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, MutableDevicePropertySpec<D, T>>> =
+        PropertyDelegateProvider { _: CompositeControlComponentSpec<D>, property ->
+            val propertyName = name ?: property.name
+            val descriptor = createPropertyDescriptorInternal(
+                propertyName = propertyName,
+                converter = converter,
+                mutable = true,
+                property = property,
+                descriptorBuilder = descriptorBuilder
+            )
+            val deviceProperty = registerProperty(object : MutableDevicePropertySpec<D, T> {
+                override val descriptor = descriptor
+                override val converter = converter
+                override suspend fun read(device: D): T? =
+                    withContext(device.coroutineContext) { device.read(propertyName) }
+
+                override suspend fun write(device: D, value: T): Unit = withContext(device.coroutineContext) {
+                    device.write(propertyName, value)
+                }
+            })
+            ReadOnlyProperty { _, _ ->
+                deviceProperty
+            }
+        }
+
+
+    override fun <I, O> action(
+        inputConverter: MetaConverter<I>,
+        outputConverter: MetaConverter<O>,
+        descriptorBuilder: ActionDescriptorBuilder.() -> Unit,
+        name: String?,
+        execute: suspend D.(I) -> O,
+    ): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, DeviceActionSpec<D, I, O>>> =
+        PropertyDelegateProvider { _: CompositeControlComponentSpec<D>, property ->
+            val actionName = name ?: property.name
+            val descriptor = createActionDescriptor(
+                actionName = actionName,
+                inputConverter = inputConverter,
+                outputConverter = outputConverter,
+                property = property,
+                descriptorBuilder = descriptorBuilder
+            )
+            val deviceAction = registerAction(object : DeviceActionSpec<D, I, O> {
+                override val descriptor = descriptor
+                override val inputConverter = inputConverter
+                override val outputConverter = outputConverter
+                override suspend fun execute(device: D, input: I): O = withContext(device.coroutineContext) {
+                    device.execute(input)
+                }
+            })
+
+            ReadOnlyProperty { _, _ ->
+                deviceAction
+            }
+        }
+
+    override suspend fun D.onOpen() {}
+    override suspend fun D.onClose() {}
+
+}
+
+public fun <D : Device> CompositeControlComponentSpec<D>.unitAction(
+    descriptorBuilder: ActionDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    execute: suspend D.() -> Unit,
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, DeviceActionSpec<D, Unit, Unit>>> =
+    action(
+        MetaConverter.unit,
+        MetaConverter.unit,
+        descriptorBuilder,
+        name
+    ) {
+        execute()
+    }
+
+
+public fun <D : Device> CompositeControlComponentSpec<D>.metaAction(
+    descriptorBuilder: ActionDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    execute: suspend D.(Meta) -> Meta,
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, DeviceActionSpec<D, Meta, Meta>>> =
+    action(
+        MetaConverter.meta,
+        MetaConverter.meta,
+        descriptorBuilder,
+        name
+    ) {
+        execute(it)
+    }
+
+/**
+ *  Basic interface for device description
+ */
+public interface CompositeDeviceSpec<D : Device> {
+    public val properties: Map<String, DevicePropertySpec<D, *>>
+
+    public val actions: Map<String, DeviceActionSpec<D, *, *>>
+
+    public val childSpecs: Map<String, ChildComponentConfig<*>>
+
+    /**
+     *  Called on `start()`
+     */
+    public suspend fun D.onOpen()
+
+    /**
+     * Called on `stop()`
+     */
+    public suspend fun D.onClose()
+
+    /**
+     * Registers a property in the spec.
+     */
+    public fun <T, P : DevicePropertySpec<D, T>> registerProperty(deviceProperty: P): P
+
+    /**
+     * Registers an action in the spec.
+     */
+    public fun <I, O> registerAction(deviceAction: DeviceActionSpec<D, I, O>): DeviceActionSpec<D, I, O>
+
+    public fun validate(device: D)
+
+    public fun createPropertyDescriptorInternal(
+        propertyName: String,
+        converter: MetaConverter<*>,
+        mutable: Boolean,
+        property: KProperty<*>,
+        descriptorBuilder: PropertyDescriptorBuilder.() -> Unit
+    ): PropertyDescriptor
+
+    public fun createActionDescriptor(
+        actionName: String,
+        inputConverter: MetaConverter<*>,
+        outputConverter: MetaConverter<*>,
+        property: KProperty<*>,
+        descriptorBuilder: ActionDescriptorBuilder.() -> Unit
+    ): ActionDescriptor
+
+    public fun <T> property(
+        converter: MetaConverter<T>,
+        descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+        name: String? = null,
+        read: suspend D.(propertyName: String) -> T?,
+    ): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, DevicePropertySpec<D, T>>>
+
+    public fun <T> mutableProperty(
+        converter: MetaConverter<T>,
+        descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+        name: String? = null,
+        read: suspend D.(propertyName: String) -> T?,
+        write: suspend D.(propertyName: String, value: T) -> Unit,
+    ): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, MutableDevicePropertySpec<D, T>>>
+
+    public fun <I, O> action(
+        inputConverter: MetaConverter<I>,
+        outputConverter: MetaConverter<O>,
+        descriptorBuilder: ActionDescriptorBuilder.() -> Unit = {},
+        name: String? = null,
+        execute: suspend D.(I) -> O,
+    ): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, DeviceActionSpec<D, I, O>>>
+}
+
+public data class DeviceLifecycleConfig(
+    val lifecycleMode: LifecycleMode = LifecycleMode.LINKED,
+    val messageBuffer: Int = 1000,
+    val startDelay: Duration = Duration.ZERO,
+    val startTimeout: Duration? = null,
+    val stopTimeout: Duration? = null,
+    val coroutineScope: CoroutineScope? = null,
+    val dispatcher: CoroutineDispatcher? = null,
+    val onError: ChildDeviceErrorHandler = ChildDeviceErrorHandler.RESTART
+) {
+    init {
+        require(messageBuffer > 0) { "Message buffer size must be positive." }
+        startTimeout?.let { require(it.isPositive()) { "Start timeout must be positive." } }
+        stopTimeout?.let { require(it.isPositive()) { "Stop timeout must be positive." } }
+    }
+}
+
+public enum class ChildDeviceErrorHandler {
+    IGNORE,
+    RESTART,
+    STOP_PARENT,
+    PROPAGATE
+}
+
+/**
+ * Base class for managing child devices. Manages lifecycle and message flow.
+ */
+public abstract class AbstractDeviceHubManager(
+    public val context: Context,
+    private val dispatcher: CoroutineDispatcher = Dispatchers.Default,
+) {
+    internal val childrenJobs: MutableMap<Name, ChildJob> = mutableMapOf()
+    public val devices: Map<Name, Device> get() = childrenJobs.mapValues { it.value.device }
+
+    internal data class ChildJob(
+        val device: Device,
+        val job: Job,
+        val lifecycleMode: LifecycleMode,
+        val messageBus: MutableSharedFlow<DeviceMessage>,
+        val meta: Meta? = null
+    )
+
+    /**
+     * A centralized bus for messages
+     */
+    public abstract val messageBus: MutableSharedFlow<DeviceMessage>
+
+    /**
+     * A centralized bus for device change events
+     */
+    public abstract val deviceChanges: MutableSharedFlow<DeviceChangeEvent>
+
+
+    /**
+     * Launches a child device with a specific lifecycle mode and error handling.
+     */
+    @OptIn(ExperimentalCoroutinesApi::class)
+    internal fun launchChild(name: Name, device: Device, config: DeviceLifecycleConfig, meta: Meta? = null): ChildJob {
+        val childMessageBus = MutableSharedFlow<DeviceMessage>(
+            replay = config.messageBuffer,
+            onBufferOverflow = BufferOverflow.DROP_OLDEST
+        )
+        val childScope = config.coroutineScope ?: context
+        val job = childScope.launch(dispatcher + CoroutineName("Child device $name")) {
+            try {
+                if (config.lifecycleMode != LifecycleMode.INDEPENDENT) {
+                    if (config.lifecycleMode == LifecycleMode.LINKED || device.lifecycleState == LifecycleState.STARTING){
+                        delay(config.startDelay)
+                        withTimeoutOrNull(config.startTimeout ?: Duration.INFINITE) {
+                            device.start()
+                        } ?: error("Timeout on start for $name")
+                    }
+                }
+
+                device.messageFlow.collect { message ->
+                    childMessageBus.emit(message.changeSource { name.plus(it) })
+                    messageBus.emit(message.changeSource { name.plus(it) })
+                }
+            } catch (ex: Exception) {
+                val errorMessage = DeviceMessage.error(ex, name)
+                messageBus.emit(errorMessage)
+
+                when (config.onError) {
+                    ChildDeviceErrorHandler.IGNORE -> context.logger.error(ex) { "Error in child device $name ignored" }
+                    ChildDeviceErrorHandler.RESTART -> {
+                        context.logger.error(ex) { "Error in child device $name, restarting" }
+                        removeDevice(name)
+                        childrenJobs[name] = launchChild(name, device, config, meta)
+                    }
+                    ChildDeviceErrorHandler.STOP_PARENT -> {
+                        context.logger.error(ex) { "Error in child device $name, stopping parent" }
+                        coroutineContext[Job]?.cancelAndJoin()
+                    }
+                    ChildDeviceErrorHandler.PROPAGATE -> {
+                        context.logger.error(ex) { "Error in child device $name propagated to parent" }
+                        throw ex
+                    }
+                }
+            } finally {
+                childrenJobs.remove(name)
+                clearReplayCache(childMessageBus)
+                deviceChanges.emit(DeviceChangeEvent.Removed(name))
+                messageBus.emit(DeviceLogMessage("Device $name stopped", sourceDevice = name))
+                if (device is ConfigurableCompositeControlComponent<*>) {
+                    device.onChildStop()
+                }
+            }
+        }
+        return ChildJob(device, job, config.lifecycleMode, childMessageBus, meta)
+    }
+
+    @OptIn(ExperimentalCoroutinesApi::class)
+    private fun <T> clearReplayCache(mutableSharedFlow: MutableSharedFlow<T>){
+        val cached = mutableSharedFlow.replayCache
+        mutableSharedFlow.resetReplayCache()
+        cached.forEach { mutableSharedFlow.tryEmit(it) }
+    }
+
+    /**
+     * Add a device to the hub and manage its lifecycle according to its spec
+     */
+    public fun addDevice(name: Name, device: Device, config: DeviceLifecycleConfig, meta: Meta? = null) {
+        val existingDevice = devices[name]
+        if (existingDevice != null) {
+            if(existingDevice == device) {
+                error("Device with name $name is already installed")
+            }
+            context.launch(device.coroutineContext) { existingDevice.stopWithTimeout(config.stopTimeout ?: Duration.INFINITE) }
+        }
+        childrenJobs[name] = launchChild(name, device, config, meta)
+
+        context.launch {
+            deviceChanges.emit(DeviceChangeEvent.Added(name, device))
+            messageBus.emit(DeviceLogMessage("Device $name added", sourceDevice = name))
+        }
+    }
+
+    public fun removeDevice(name: Name) {
+        childrenJobs[name]?.let { childJob ->
+            context.launch(childJob.device.coroutineContext) {
+                val timeout = when (childJob.lifecycleMode) {
+                    LifecycleMode.INDEPENDENT -> childJob.device.meta["stopTimeout".asName()]?.value?.let {
+                        Duration.parse(it.toString())
+                    } ?: Duration.INFINITE
+
+                    else -> Duration.INFINITE
+                }
+                withTimeoutOrNull(timeout) {
+                    childJob.job.cancelAndJoin()
+                    childJob.device.stop()
+                } ?: error("Timeout on stop for $name")
+            }
+            childrenJobs.remove(name)
+            context.launch {
+                messageBus.emit(DeviceLogMessage("Device $name removed", sourceDevice = name))
+                deviceChanges.emit(DeviceChangeEvent.Removed(name))
+            }
+        }
+    }
+
+    /**
+     * Change lifecycle mode of a child device
+     */
+    public fun changeLifecycleMode(name: Name, mode: LifecycleMode) {
+        val job = childrenJobs[name] ?: error("Device with name '$name' is not found")
+        val config = DeviceLifecycleConfig(lifecycleMode = mode, messageBuffer = job.messageBus.replayCache.size)
+        context.launch {
+            job.job.cancelAndJoin()
+            childrenJobs[name] = launchChild(name, job.device, config, job.meta)
+        }
+    }
+
+    /**
+     * Get local message bus for a child device
+     */
+    public fun getChildMessageBus(name: Name) : MutableSharedFlow<DeviceMessage>? = childrenJobs[name]?.messageBus
+
+    /**
+     * Method for explicit call when child device is stopped.
+     */
+    internal open fun onChildStop(){
+
+    }
+}
+
+
+private class DeviceHubManagerImpl(context: Context, dispatcher: CoroutineDispatcher = Dispatchers.Default) : AbstractDeviceHubManager(context, dispatcher){
+    override val messageBus: MutableSharedFlow<DeviceMessage> = MutableSharedFlow(
+        replay = 1000,
+        onBufferOverflow = BufferOverflow.DROP_OLDEST
+    )
+    override val deviceChanges: MutableSharedFlow<DeviceChangeEvent> = MutableSharedFlow(replay = 1)
+}
+
+/**
+ * An interface for a device that contains other devices as children.
+ */
+public interface CompositeControlComponent : Device {
+    /**
+     * A centralized flow of all device messages from this node and all its children
+     */
+    public val messageBus: SharedFlow<DeviceMessage>
+
+    /**
+     * A map of child devices
+     */
+    public val devices: Map<Name, Device>
+}
+
+/**
+ * A base class for devices created from specification, using AbstractDeviceHubManager for children management
+ */
+public open class ConfigurableCompositeControlComponent<D : Device>(
+    public open val spec: CompositeControlComponentSpec<D>,
+    context: Context,
+    meta: Meta = Meta.EMPTY,
+    config: DeviceLifecycleConfig = DeviceLifecycleConfig(),
+    private val hubManager: AbstractDeviceHubManager = DeviceHubManagerImpl(context, config.dispatcher ?: Dispatchers.Default),
+) : DeviceBase<D>(context, meta), CompositeControlComponent {
+
+    override val properties: Map<String, DevicePropertySpec<D, *>>
+        get() = spec.properties
+
+    override val actions: Map<String, DeviceActionSpec<D, *, *>>
+        get() = spec.actions
+
+    final override val messageBus: MutableSharedFlow<DeviceMessage>
+        get() = hubManager.messageBus
+
+    public val deviceChanges: MutableSharedFlow<DeviceChangeEvent>
+        get() = hubManager.deviceChanges
+
+    public val aggregatedMessageFlow: SharedFlow<DeviceMessage>
+        get() = hubManager.messageBus
+
+    init {
+        spec.childSpecs.forEach{ (name, childSpec) ->
+            val childDevice = ConfigurableCompositeControlComponent(childSpec.spec, context, childSpec.meta ?: Meta.EMPTY, childSpec.config)
+            addDevice(childSpec.name, childDevice, childSpec.config, childSpec.meta)
+        }
+
+        spec.actions.values.forEach { actionSpec ->
+            launch {
+                val actionName = actionSpec.name
+                messageFlow.filterIsInstance<ActionExecuteMessage>().filter { it.action == actionName }.onEach {
+                    val result = execute(actionName, it.argument)
+                    messageBus.emit(
+                        ActionResultMessage(
+                            action = actionName,
+                            result = result,
+                            requestId = it.requestId,
+                            sourceDevice = id.asName()
+                        )
+                    )
+                }.launchIn(this)
+            }
+        }
+    }
+
+    override suspend fun onStart() {
+        with(spec) {
+            self.onOpen()
+            validate(self)
+        }
+        hubManager.devices.values.filter {
+            it.lifecycleState != LifecycleState.STARTED && it.lifecycleState != LifecycleState.STARTING
+        }.forEach {
+            if (hubManager.childrenJobs[it.id.parseAsName()]?.lifecycleMode != LifecycleMode.LAZY) {
+                it.start()
+            }
+        }
+    }
+
+    private suspend fun getTimeout(device: Device): Duration {
+        return (hubManager.childrenJobs[device.id.parseAsName()]?.lifecycleMode ?:  LifecycleMode.LINKED).let{
+            if(it == LifecycleMode.INDEPENDENT)
+                it.name.let{ meta["stopTimeout".parseAsName()]?.let { durationMeta ->
+                    Duration.parse(durationMeta.value.toString())
+                } ?: Duration.INFINITE }
+            else Duration.INFINITE
+        }
+    }
+
+    override suspend fun onStop() {
+        hubManager.devices.values.forEach {
+            launch(it.coroutineContext){
+                withTimeoutOrNull(getTimeout(it)){
+                    it.stop()
+                }
+            }
+        }
+        with(spec) {
+            self.onClose()
+        }
+    }
+
+    override fun toString(): String = "Device(spec=$spec)"
+
+    internal open fun onChildStop() {
+    }
+
+    /**
+     * Add existing device to this hub
+     */
+    private fun addDevice(name: Name = device.id.asName(), device: Device, config: DeviceLifecycleConfig = DeviceLifecycleConfig(), meta: Meta? = null) {
+        hubManager.addDevice(name, device, config, meta)
+    }
+
+    /**
+     * Remove a child device from the hub by name.
+     */
+    private fun removeDevice(name: Name) {
+        hubManager.removeDevice(name)
+    }
+
+    /**
+     * Get list of all children devices
+     */
+    public override val devices: Map<Name, Device>
+        get() = hubManager.devices
+
+    /**
+     * Get child device from this hub by name
+     */
+    public fun <CD : ConfigurableCompositeControlComponent<CD>> getChildDevice(name: Name): ConfigurableCompositeControlComponent<CD> =
+        hubManager.devices[name] as? ConfigurableCompositeControlComponent<CD>? ?: error("Device $name not found")
+
+    public fun <CD: ConfigurableCompositeControlComponent<CD>> childDevice(name: Name? = null):
+            PropertyDelegateProvider<ConfigurableCompositeControlComponent<D>, ReadOnlyProperty<ConfigurableCompositeControlComponent<D>, CD>>
+            = PropertyDelegateProvider{ thisRef, property ->
+        ReadOnlyProperty{ _, _ ->
+            val deviceName = name ?: property.name.asName()
+            thisRef.devices[deviceName] as? CD ?: error("Device $deviceName not found")
+        }
+    }
+
+    /**
+     * Get child device message bus by name
+     */
+    public fun getChildMessageBus(name: Name): SharedFlow<DeviceMessage>? = hubManager.getChildMessageBus(name)
+
+    /**
+     * Get device, using delegate method
+     */
+    public inline operator fun <reified D : Device> get(name: Name): D? = devices[name] as? D
+
+    /**
+     * Get device, using delegate method
+     */
+    public inline operator fun <reified D : Device> get(name: String): D? = devices[name.asName()] as? D
+
+}
+
+public suspend fun WithLifeCycle.stopWithTimeout(timeout: Duration = Duration.INFINITE) {
+    withTimeoutOrNull(timeout) {
+        stop()
+    }
+}
+
+public interface ChildComponentConfig<CD: Device>{
+    public val spec: CompositeControlComponentSpec<CD>
+    public val config: DeviceLifecycleConfig
+    public val meta: Meta?
+    public val name: Name
+}
diff --git a/controls-core/src/commonMain/kotlin/space/kscience/controls/spec/CompositeControlComponentsDelegates.kt b/controls-core/src/commonMain/kotlin/space/kscience/controls/spec/CompositeControlComponentsDelegates.kt
new file mode 100644
index 0000000..b042163
--- /dev/null
+++ b/controls-core/src/commonMain/kotlin/space/kscience/controls/spec/CompositeControlComponentsDelegates.kt
@@ -0,0 +1,384 @@
+package space.kscience.controls.spec
+
+import kotlinx.coroutines.Deferred
+import space.kscience.controls.api.ActionDescriptorBuilder
+import space.kscience.controls.api.Device
+import space.kscience.controls.api.PropertyDescriptorBuilder
+import space.kscience.controls.api.id
+import space.kscience.dataforge.meta.Meta
+import space.kscience.dataforge.meta.MetaConverter
+import space.kscience.dataforge.meta.ValueType
+import space.kscience.dataforge.meta.descriptors.MetaDescriptor
+import space.kscience.dataforge.meta.string
+import kotlin.properties.PropertyDelegateProvider
+import kotlin.properties.ReadOnlyProperty
+import kotlin.reflect.KMutableProperty1
+import kotlin.reflect.KProperty1
+
+/**
+ * Create a [MetaConverter] for enum values
+ */
+public fun <E : Enum<E>> createEnumConverter(enumValues: Array<E>): MetaConverter<E> = object : MetaConverter<E> {
+    override val descriptor: MetaDescriptor = MetaDescriptor {
+        valueType(ValueType.STRING)
+        allowedValues(enumValues.map { it.name })
+    }
+
+    override fun readOrNull(source: Meta): E? {
+        val value = source.value ?: return null
+        return enumValues.firstOrNull { it.name == value.string }
+    }
+
+    override fun convert(obj: E): Meta = Meta(obj.name)
+}
+
+/**
+ * A read-only device property that delegates reading to a device [KProperty1]
+ */
+public fun <T, D : Device> CompositeControlComponentSpec<D>.property(
+    converter: MetaConverter<T>,
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    read: suspend D.(propertyName: String) -> T?,
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, DevicePropertySpec<D, T>>> {
+    return  property(converter, descriptorBuilder, name, read)
+}
+
+/**
+ * Mutable property that delegates reading and writing to a device [KMutableProperty1]
+ */
+public fun <T, D : Device> CompositeControlComponentSpec<D>.mutableProperty(
+    converter: MetaConverter<T>,
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    read: suspend D.(propertyName: String) -> T?,
+    write: suspend D.(propertyName: String, value: T) -> Unit,
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, MutableDevicePropertySpec<D, T>>> {
+    return  mutableProperty(converter, descriptorBuilder, name, read, write)
+}
+
+/**
+ * Register a mutable logical property (without a corresponding physical state) for a device
+ */
+public fun <T, D : DeviceBase<D>> CompositeControlComponentSpec<D>.logical(
+    converter: MetaConverter<T>,
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, MutableDevicePropertySpec<D, T>>> =
+    mutableProperty(
+        converter,
+        descriptorBuilder,
+        name,
+        read = { propertyName -> getProperty(propertyName)?.let(converter::readOrNull) },
+        write = { propertyName, value -> writeProperty(propertyName, converter.convert(value)) }
+    )
+
+/**
+ * Creates a boolean property for a device.
+ */
+public fun <D : Device> CompositeControlComponentSpec<D>.boolean(
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    read: suspend D.(propertyName: String) -> Boolean?,
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, DevicePropertySpec<D, Boolean>>> =
+    property(MetaConverter.boolean, descriptorBuilder, name, read)
+
+/**
+ * Creates a mutable boolean property for a device.
+ */
+public fun <D : Device> CompositeControlComponentSpec<D>.booleanMutable(
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    read: suspend D.(propertyName: String) -> Boolean?,
+    write: suspend D.(propertyName: String, value: Boolean) -> Unit
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, MutableDevicePropertySpec<D, Boolean>>> =
+    mutableProperty(MetaConverter.boolean, descriptorBuilder, name, read, write)
+
+/**
+ * Creates a read-only number property for a device.
+ */
+public fun <D : Device> CompositeControlComponentSpec<D>.number(
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    read: suspend D.(propertyName: String) -> Number?,
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, DevicePropertySpec<D, Number>>> =
+    property(MetaConverter.number, descriptorBuilder, name, read)
+
+/**
+ * Creates a mutable number property for a device.
+ */
+public fun <D : Device> CompositeControlComponentSpec<D>.numberMutable(
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    read: suspend D.(propertyName: String) -> Number?,
+    write: suspend D.(propertyName: String, value: Number) -> Unit
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, MutableDevicePropertySpec<D, Number>>> =
+    mutableProperty(MetaConverter.number, descriptorBuilder, name, read, write)
+
+
+/**
+ * Creates a read-only double property for a device.
+ */
+public fun <D : Device> CompositeControlComponentSpec<D>.double(
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    read: suspend D.(propertyName: String) -> Double?,
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, DevicePropertySpec<D, Double>>> =
+    property(MetaConverter.double, descriptorBuilder, name, read)
+
+/**
+ * Creates a mutable double property for a device.
+ */
+public fun <D : Device> CompositeControlComponentSpec<D>.doubleMutable(
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    read: suspend D.(propertyName: String) -> Double?,
+    write: suspend D.(propertyName: String, value: Double) -> Unit
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, MutableDevicePropertySpec<D, Double>>> =
+    mutableProperty(MetaConverter.double, descriptorBuilder, name, read, write)
+
+/**
+ * Creates a read-only string property for a device.
+ */
+public fun <D : Device> CompositeControlComponentSpec<D>.string(
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    read: suspend D.(propertyName: String) -> String?
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, DevicePropertySpec<D, String>>> =
+    property(MetaConverter.string, descriptorBuilder, name, read)
+
+/**
+ * Creates a mutable string property for a device.
+ */
+public fun <D : Device> CompositeControlComponentSpec<D>.stringMutableProperty(
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    read: suspend D.(propertyName: String) -> String?,
+    write: suspend D.(propertyName: String, value: String) -> Unit
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, MutableDevicePropertySpec<D, String>>> =
+    mutableProperty(MetaConverter.string, descriptorBuilder, name, read, write)
+
+/**
+ * Creates a read-only meta property for a device.
+ */
+public fun <D : Device> CompositeControlComponentSpec<D>.meta(
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    read: suspend D.(propertyName: String) -> Meta?,
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, DevicePropertySpec<D, Meta>>> =
+    property(MetaConverter.meta, descriptorBuilder, name, read)
+
+/**
+ * Creates a mutable meta property for a device.
+ */
+public fun <D : Device> CompositeControlComponentSpec<D>.metaMutable(
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    read: suspend D.(propertyName: String) -> Meta?,
+    write: suspend D.(propertyName: String, value: Meta) -> Unit
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, MutableDevicePropertySpec<D, Meta>>> =
+    mutableProperty(MetaConverter.meta, descriptorBuilder, name, read, write)
+
+/**
+ * Creates a read-only enum property for a device.
+ */
+public fun <E : Enum<E>, D : Device> CompositeControlComponentSpec<D>.enum(
+    enumValues: Array<E>,
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    read: suspend D.(propertyName: String) -> E?,
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, DevicePropertySpec<D, E>>> {
+    val converter = createEnumConverter(enumValues)
+    return property(converter, descriptorBuilder, name, read)
+}
+
+/**
+ * Creates a mutable enum property for a device.
+ */
+public fun <E : Enum<E>, D : Device> CompositeControlComponentSpec<D>.enumMutable(
+    enumValues: Array<E>,
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    read: suspend D.(propertyName: String) -> E?,
+    write: suspend D.(propertyName: String, value: E) -> Unit
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, MutableDevicePropertySpec<D, E>>> {
+    val converter = createEnumConverter(enumValues)
+    return mutableProperty(converter, descriptorBuilder, name, read, write)
+}
+
+/**
+ * Creates a read-only float property for a device.
+ */
+public fun <D : Device> CompositeControlComponentSpec<D>.float(
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    read: suspend D.(propertyName: String) -> Float?,
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, DevicePropertySpec<D, Float>>> =
+    property(MetaConverter.float, descriptorBuilder, name, read)
+
+/**
+ * Creates a mutable float property for a device.
+ */
+public fun <D : Device> CompositeControlComponentSpec<D>.floatMutable(
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    read: suspend D.(propertyName: String) -> Float?,
+    write: suspend D.(propertyName: String, value: Float) -> Unit
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, MutableDevicePropertySpec<D, Float>>> =
+    mutableProperty(MetaConverter.float, descriptorBuilder, name, read, write)
+
+/**
+ * Creates a read-only long property for a device.
+ */
+public fun <D : Device> CompositeControlComponentSpec<D>.long(
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    read: suspend D.(propertyName: String) -> Long?,
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, DevicePropertySpec<D, Long>>> =
+    property(MetaConverter.long, descriptorBuilder, name, read)
+
+/**
+ * Creates a mutable long property for a device.
+ */
+public fun <D : Device> CompositeControlComponentSpec<D>.longMutable(
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    read: suspend D.(propertyName: String) -> Long?,
+    write: suspend D.(propertyName: String, value: Long) -> Unit
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, MutableDevicePropertySpec<D, Long>>> =
+    mutableProperty(MetaConverter.long, descriptorBuilder, name, read, write)
+
+/**
+ * Creates a read-only int property for a device.
+ */
+public fun <D : Device> CompositeControlComponentSpec<D>.int(
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    read: suspend D.(propertyName: String) -> Int?,
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, DevicePropertySpec<D, Int>>> =
+    property(MetaConverter.int, descriptorBuilder, name, read)
+
+/**
+ * Creates a mutable int property for a device.
+ */
+public fun <D : Device> CompositeControlComponentSpec<D>.intMutable(
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    read: suspend D.(propertyName: String) -> Int?,
+    write: suspend D.(propertyName: String, value: Int) -> Unit
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, MutableDevicePropertySpec<D, Int>>> =
+    mutableProperty(MetaConverter.int, descriptorBuilder, name, read, write)
+
+/**
+ * Creates a read-only list property for a device.
+ */
+public fun <T, D : Device> CompositeControlComponentSpec<D>.list(
+    converter: MetaConverter<List<T>>,
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    read: suspend D.(propertyName: String) -> List<T>?,
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, DevicePropertySpec<D, List<T>>>> =
+    property(converter, descriptorBuilder, name, read)
+
+/**
+ * Creates a mutable list property for a device.
+ */
+public fun <T, D : Device> CompositeControlComponentSpec<D>.listMutable(
+    converter: MetaConverter<List<T>>,
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    read: suspend D.(propertyName: String) -> List<T>?,
+    write: suspend D.(propertyName: String, value: List<T>) -> Unit
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, MutableDevicePropertySpec<D, List<T>>>> =
+    mutableProperty(converter, descriptorBuilder, name, read, write)
+
+
+public fun <I, O, D : Device> CompositeControlComponentSpec<D>.asyncActionProperty(
+    inputConverter: MetaConverter<I>,
+    outputConverter: MetaConverter<O>,
+    descriptorBuilder: ActionDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    execute: suspend D.(I) -> Deferred<O>,
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, DeviceActionSpec<D, I, O>>> =
+    action(inputConverter, outputConverter, descriptorBuilder, name) { input ->
+        execute(input).await()
+    }
+
+public fun <T, D : Device> CompositeControlComponentSpec<D>.metaProperty(
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    read: suspend D.(propertyName: String) -> Meta?,
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, DevicePropertySpec<D, Meta>>> =
+    property(MetaConverter.meta, descriptorBuilder, name, read)
+
+
+public fun <T, D : Device> CompositeControlComponentSpec<D>.mutableMetaProperty(
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    read: suspend D.(propertyName: String) -> Meta?,
+    write: suspend D.(propertyName: String, value: Meta) -> Unit
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, MutableDevicePropertySpec<D, Meta>>> =
+    mutableProperty(MetaConverter.meta, descriptorBuilder, name, read, write)
+
+/**
+ * An action that takes no parameters and returns no values
+ */
+public fun <T, D : Device> CompositeControlComponentSpec<D>.unitAction(
+    descriptorBuilder: ActionDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    execute: suspend D.() -> Unit,
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, DeviceActionSpec<D, Unit, Unit>>> =
+    action(
+        MetaConverter.unit,
+        MetaConverter.unit,
+        descriptorBuilder,
+        name
+    ) {
+        execute()
+    }
+
+public fun <I, O, D : Device> CompositeControlComponentSpec<D>.asyncAction(
+    inputConverter: MetaConverter<I>,
+    outputConverter: MetaConverter<O>,
+    descriptorBuilder: ActionDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    execute: suspend D.(I) -> Deferred<O>,
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, DeviceActionSpec<D, I, O>>> =
+    action(
+        inputConverter,
+        outputConverter,
+        descriptorBuilder,
+        name
+    ) {
+        execute(it).await()
+    }
+
+/**
+ * An action that takes [Meta] and returns [Meta]. No conversions are done
+ */
+public fun <T, D : Device> CompositeControlComponentSpec<D>.metaAction(
+    descriptorBuilder: ActionDescriptorBuilder.() -> Unit = {},
+    name: String? = null,
+    execute: suspend D.(Meta) -> Meta,
+): PropertyDelegateProvider<CompositeControlComponentSpec<D>, ReadOnlyProperty<CompositeControlComponentSpec<D>, DeviceActionSpec<D, Meta, Meta>>> =
+    action(
+        MetaConverter.meta,
+        MetaConverter.meta,
+        descriptorBuilder,
+        name
+    ) {
+        execute(it)
+    }
+
+/**
+ * Throw an exception if device does not have all properties and actions defined by this specification
+ */
+public fun CompositeControlComponentSpec<*>.validate(device: Device) {
+    properties.map { it.value.descriptor }.forEach { specProperty ->
+        check(specProperty in device.propertyDescriptors) { "Property ${specProperty.name} not registered in ${device.id}" }
+    }
+
+    actions.map { it.value.descriptor }.forEach { specAction ->
+        check(specAction in device.actionDescriptors) { "Action ${specAction.name} not registered in ${device.id}" }
+    }
+}
\ No newline at end of file
diff --git a/controls-core/src/commonMain/kotlin/space/kscience/controls/spec/DeviceSpec.kt b/controls-core/src/commonMain/kotlin/space/kscience/controls/spec/DeviceSpec.kt
index c6f8b0a..945fe38 100644
--- a/controls-core/src/commonMain/kotlin/space/kscience/controls/spec/DeviceSpec.kt
+++ b/controls-core/src/commonMain/kotlin/space/kscience/controls/spec/DeviceSpec.kt
@@ -44,24 +44,24 @@ public abstract class DeviceSpec<D : Device> {
 
     public fun <T> property(
         converter: MetaConverter<T>,
-        descriptorBuilder: PropertyDescriptor.() -> Unit = {},
+        descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
         name: String? = null,
         read: suspend D.(propertyName: String) -> T?,
     ): PropertyDelegateProvider<DeviceSpec<D>, ReadOnlyProperty<DeviceSpec<D>, DevicePropertySpec<D, T>>> =
         PropertyDelegateProvider { _: DeviceSpec<D>, property ->
             val propertyName = name ?: property.name
-            val deviceProperty = object : DevicePropertySpec<D, T> {
-
-                override val descriptor: PropertyDescriptor = PropertyDescriptor(propertyName).apply {
-                    converter.descriptor?.let { converterDescriptor ->
-                        metaDescriptor {
-                            from(converterDescriptor)
-                        }
+            val descriptor = propertyDescriptor(propertyName) {
+                mutable = false
+                converter.descriptor?.let { converterDescriptor ->
+                    metaDescriptor {
+                        from(converterDescriptor)
                     }
-                    fromSpec(property)
-                    descriptorBuilder()
                 }
-
+                fromSpec(property)
+                descriptorBuilder()
+            }
+            val deviceProperty = object : DevicePropertySpec<D, T> {
+                override val descriptor = descriptor
                 override val converter: MetaConverter<T> = converter
 
                 override suspend fun read(device: D): T? =
@@ -75,26 +75,25 @@ public abstract class DeviceSpec<D : Device> {
 
     public fun <T> mutableProperty(
         converter: MetaConverter<T>,
-        descriptorBuilder: PropertyDescriptor.() -> Unit = {},
+        descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
         name: String? = null,
         read: suspend D.(propertyName: String) -> T?,
         write: suspend D.(propertyName: String, value: T) -> Unit,
     ): PropertyDelegateProvider<DeviceSpec<D>, ReadOnlyProperty<DeviceSpec<D>, MutableDevicePropertySpec<D, T>>> =
         PropertyDelegateProvider { _: DeviceSpec<D>, property: KProperty<*> ->
             val propertyName = name ?: property.name
-            val deviceProperty = object : MutableDevicePropertySpec<D, T> {
-                override val descriptor: PropertyDescriptor = PropertyDescriptor(
-                    propertyName,
-                    mutable = true
-                ).apply {
-                    converter.descriptor?.let { converterDescriptor ->
-                        metaDescriptor {
-                            from(converterDescriptor)
-                        }
+            val descriptor = propertyDescriptor(propertyName) {
+                this.mutable = true
+                converter.descriptor?.let { converterDescriptor ->
+                    metaDescriptor {
+                        from(converterDescriptor)
                     }
-                    fromSpec(property)
-                    descriptorBuilder()
                 }
+                fromSpec(property)
+                descriptorBuilder()
+            }
+            val deviceProperty = object : MutableDevicePropertySpec<D, T> {
+                override val descriptor = descriptor
                 override val converter: MetaConverter<T> = converter
 
                 override suspend fun read(device: D): T? =
@@ -119,30 +118,28 @@ public abstract class DeviceSpec<D : Device> {
     public fun <I, O> action(
         inputConverter: MetaConverter<I>,
         outputConverter: MetaConverter<O>,
-        descriptorBuilder: ActionDescriptor.() -> Unit = {},
+        descriptorBuilder: ActionDescriptorBuilder.() -> Unit = {},
         name: String? = null,
         execute: suspend D.(I) -> O,
     ): PropertyDelegateProvider<DeviceSpec<D>, ReadOnlyProperty<DeviceSpec<D>, DeviceActionSpec<D, I, O>>> =
         PropertyDelegateProvider { _: DeviceSpec<D>, property: KProperty<*> ->
             val actionName = name ?: property.name
-            val deviceAction = object : DeviceActionSpec<D, I, O> {
-                override val descriptor: ActionDescriptor = ActionDescriptor(actionName).apply {
-                    inputConverter.descriptor?.let { converterDescriptor ->
-                        inputMetaDescriptor = MetaDescriptor {
-                            from(converterDescriptor)
-                            from(inputMetaDescriptor)
-                        }
+            val descriptor = actionDescriptor(actionName) {
+                inputConverter.descriptor?.let { converterDescriptor ->
+                    inputMeta {
+                        from(converterDescriptor)
                     }
-                    outputConverter.descriptor?.let { converterDescriptor ->
-                        outputMetaDescriptor = MetaDescriptor {
-                            from(converterDescriptor)
-                            from(outputMetaDescriptor)
-                        }
-                    }
-
-                    fromSpec(property)
-                    descriptorBuilder()
                 }
+                outputConverter.descriptor?.let { converterDescriptor ->
+                    outputMeta {
+                        from(converterDescriptor)
+                    }
+                }
+                fromSpec(property)
+                descriptorBuilder()
+            }
+            val deviceAction = object : DeviceActionSpec<D, I, O> {
+                override val descriptor: ActionDescriptor = descriptor
 
                 override val inputConverter: MetaConverter<I> = inputConverter
                 override val outputConverter: MetaConverter<O> = outputConverter
@@ -162,7 +159,7 @@ public abstract class DeviceSpec<D : Device> {
  * An action that takes no parameters and returns no values
  */
 public fun <D : Device> DeviceSpec<D>.unitAction(
-    descriptorBuilder: ActionDescriptor.() -> Unit = {},
+    descriptorBuilder: ActionDescriptorBuilder.() -> Unit = {},
     name: String? = null,
     execute: suspend D.() -> Unit,
 ): PropertyDelegateProvider<DeviceSpec<D>, ReadOnlyProperty<DeviceSpec<D>, DeviceActionSpec<D, Unit, Unit>>> =
@@ -179,7 +176,7 @@ public fun <D : Device> DeviceSpec<D>.unitAction(
  * An action that takes [Meta] and returns [Meta]. No conversions are done
  */
 public fun <D : Device> DeviceSpec<D>.metaAction(
-    descriptorBuilder: ActionDescriptor.() -> Unit = {},
+    descriptorBuilder: ActionDescriptorBuilder.() -> Unit = {},
     name: String? = null,
     execute: suspend D.(Meta) -> Meta,
 ): PropertyDelegateProvider<DeviceSpec<D>, ReadOnlyProperty<DeviceSpec<D>, DeviceActionSpec<D, Meta, Meta>>> =
diff --git a/controls-core/src/commonMain/kotlin/space/kscience/controls/spec/fromSpec.kt b/controls-core/src/commonMain/kotlin/space/kscience/controls/spec/fromSpec.kt
index ad5862b..57a9b4a 100644
--- a/controls-core/src/commonMain/kotlin/space/kscience/controls/spec/fromSpec.kt
+++ b/controls-core/src/commonMain/kotlin/space/kscience/controls/spec/fromSpec.kt
@@ -1,10 +1,10 @@
 package space.kscience.controls.spec
 
-import space.kscience.controls.api.ActionDescriptor
-import space.kscience.controls.api.PropertyDescriptor
+import space.kscience.controls.api.ActionDescriptorBuilder
+import space.kscience.controls.api.PropertyDescriptorBuilder
 import kotlin.reflect.KProperty
 
 
-internal expect fun PropertyDescriptor.fromSpec(property: KProperty<*>)
+internal expect fun PropertyDescriptorBuilder.fromSpec(property: KProperty<*>)
 
-internal expect fun ActionDescriptor.fromSpec(property: KProperty<*>)
\ No newline at end of file
+internal expect fun ActionDescriptorBuilder.fromSpec(property: KProperty<*>)
\ No newline at end of file
diff --git a/controls-core/src/commonMain/kotlin/space/kscience/controls/spec/propertySpecDelegates.kt b/controls-core/src/commonMain/kotlin/space/kscience/controls/spec/propertySpecDelegates.kt
index efb66a7..34440fc 100644
--- a/controls-core/src/commonMain/kotlin/space/kscience/controls/spec/propertySpecDelegates.kt
+++ b/controls-core/src/commonMain/kotlin/space/kscience/controls/spec/propertySpecDelegates.kt
@@ -1,8 +1,7 @@
 package space.kscience.controls.spec
 
 import space.kscience.controls.api.Device
-import space.kscience.controls.api.PropertyDescriptor
-import space.kscience.controls.api.metaDescriptor
+import space.kscience.controls.api.PropertyDescriptorBuilder
 import space.kscience.dataforge.meta.Meta
 import space.kscience.dataforge.meta.MetaConverter
 import space.kscience.dataforge.meta.ValueType
@@ -17,7 +16,7 @@ import kotlin.reflect.KProperty1
 public fun <T, D : Device> DeviceSpec<D>.property(
     converter: MetaConverter<T>,
     readOnlyProperty: KProperty1<D, T>,
-    descriptorBuilder: PropertyDescriptor.() -> Unit = {},
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
 ): PropertyDelegateProvider<DeviceSpec<D>, ReadOnlyProperty<DeviceSpec<D>, DevicePropertySpec<D, T>>> = property(
     converter,
     descriptorBuilder,
@@ -31,7 +30,7 @@ public fun <T, D : Device> DeviceSpec<D>.property(
 public fun <T, D : Device> DeviceSpec<D>.mutableProperty(
     converter: MetaConverter<T>,
     readWriteProperty: KMutableProperty1<D, T>,
-    descriptorBuilder: PropertyDescriptor.() -> Unit = {},
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
 ): PropertyDelegateProvider<DeviceSpec<D>, ReadOnlyProperty<DeviceSpec<D>, MutableDevicePropertySpec<D, T>>> =
     mutableProperty(
         converter,
@@ -49,7 +48,7 @@ public fun <T, D : Device> DeviceSpec<D>.mutableProperty(
  */
 public fun <T, D : DeviceBase<D>> DeviceSpec<D>.property(
     converter: MetaConverter<T>,
-    descriptorBuilder: PropertyDescriptor.() -> Unit = {},
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
     name: String? = null,
 ): PropertyDelegateProvider<DeviceSpec<D>, ReadOnlyProperty<DeviceSpec<D>, DevicePropertySpec<D, T>>> =
     property(
@@ -60,7 +59,7 @@ public fun <T, D : DeviceBase<D>> DeviceSpec<D>.property(
     )
 
 public fun <D : Device> DeviceSpec<D>.booleanProperty(
-    descriptorBuilder: PropertyDescriptor.() -> Unit = {},
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
     name: String? = null,
     read: suspend D.(propertyName: String) -> Boolean?
 ): PropertyDelegateProvider<DeviceSpec<D>, ReadOnlyProperty<DeviceSpec<D>, DevicePropertySpec<D, Boolean>>> = property(
@@ -76,8 +75,8 @@ public fun <D : Device> DeviceSpec<D>.booleanProperty(
 )
 
 private inline fun numberDescriptor(
-    crossinline descriptorBuilder: PropertyDescriptor.() -> Unit = {}
-): PropertyDescriptor.() -> Unit = {
+    crossinline descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {}
+): PropertyDescriptorBuilder.() -> Unit = {
     metaDescriptor {
         valueType(ValueType.NUMBER)
     }
@@ -85,7 +84,7 @@ private inline fun numberDescriptor(
 }
 
 public fun <D : Device> DeviceSpec<D>.numberProperty(
-    descriptorBuilder: PropertyDescriptor.() -> Unit = {},
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
     name: String? = null,
     read: suspend D.(propertyName: String) -> Number?
 ): PropertyDelegateProvider<DeviceSpec<D>, ReadOnlyProperty<DeviceSpec<D>, DevicePropertySpec<D, Number>>> = property(
@@ -96,7 +95,7 @@ public fun <D : Device> DeviceSpec<D>.numberProperty(
 )
 
 public fun <D : Device> DeviceSpec<D>.doubleProperty(
-    descriptorBuilder: PropertyDescriptor.() -> Unit = {},
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
     name: String? = null,
     read: suspend D.(propertyName: String) -> Double?
 ): PropertyDelegateProvider<DeviceSpec<D>, ReadOnlyProperty<DeviceSpec<D>, DevicePropertySpec<D, Double>>> = property(
@@ -107,7 +106,7 @@ public fun <D : Device> DeviceSpec<D>.doubleProperty(
 )
 
 public fun <D : Device> DeviceSpec<D>.stringProperty(
-    descriptorBuilder: PropertyDescriptor.() -> Unit = {},
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
     name: String? = null,
     read: suspend D.(propertyName: String) -> String?
 ): PropertyDelegateProvider<DeviceSpec<D>, ReadOnlyProperty<DeviceSpec<D>, DevicePropertySpec<D, String>>> = property(
@@ -123,7 +122,7 @@ public fun <D : Device> DeviceSpec<D>.stringProperty(
 )
 
 public fun <D : Device> DeviceSpec<D>.metaProperty(
-    descriptorBuilder: PropertyDescriptor.() -> Unit = {},
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
     name: String? = null,
     read: suspend D.(propertyName: String) -> Meta?
 ): PropertyDelegateProvider<DeviceSpec<D>, ReadOnlyProperty<DeviceSpec<D>, DevicePropertySpec<D, Meta>>> = property(
@@ -147,7 +146,7 @@ public fun <D : Device> DeviceSpec<D>.metaProperty(
  */
 public fun <T, D : DeviceBase<D>> DeviceSpec<D>.mutableProperty(
     converter: MetaConverter<T>,
-    descriptorBuilder: PropertyDescriptor.() -> Unit = {},
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
     name: String? = null,
 ): PropertyDelegateProvider<DeviceSpec<D>, ReadOnlyProperty<DeviceSpec<D>, MutableDevicePropertySpec<D, T>>> =
     mutableProperty(
@@ -159,7 +158,7 @@ public fun <T, D : DeviceBase<D>> DeviceSpec<D>.mutableProperty(
     )
 
 public fun <D : Device> DeviceSpec<D>.mutableBooleanProperty(
-    descriptorBuilder: PropertyDescriptor.() -> Unit = {},
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
     name: String? = null,
     read: suspend D.(propertyName: String) -> Boolean?,
     write: suspend D.(propertyName: String, value: Boolean) -> Unit
@@ -179,7 +178,7 @@ public fun <D : Device> DeviceSpec<D>.mutableBooleanProperty(
 
 
 public fun <D : Device> DeviceSpec<D>.mutableNumberProperty(
-    descriptorBuilder: PropertyDescriptor.() -> Unit = {},
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
     name: String? = null,
     read: suspend D.(propertyName: String) -> Number,
     write: suspend D.(propertyName: String, value: Number) -> Unit
@@ -187,7 +186,7 @@ public fun <D : Device> DeviceSpec<D>.mutableNumberProperty(
     mutableProperty(MetaConverter.number, numberDescriptor(descriptorBuilder), name, read, write)
 
 public fun <D : Device> DeviceSpec<D>.mutableDoubleProperty(
-    descriptorBuilder: PropertyDescriptor.() -> Unit = {},
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
     name: String? = null,
     read: suspend D.(propertyName: String) -> Double,
     write: suspend D.(propertyName: String, value: Double) -> Unit
@@ -195,7 +194,7 @@ public fun <D : Device> DeviceSpec<D>.mutableDoubleProperty(
     mutableProperty(MetaConverter.double, numberDescriptor(descriptorBuilder), name, read, write)
 
 public fun <D : Device> DeviceSpec<D>.mutableStringProperty(
-    descriptorBuilder: PropertyDescriptor.() -> Unit = {},
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
     name: String? = null,
     read: suspend D.(propertyName: String) -> String,
     write: suspend D.(propertyName: String, value: String) -> Unit
@@ -203,7 +202,7 @@ public fun <D : Device> DeviceSpec<D>.mutableStringProperty(
     mutableProperty(MetaConverter.string, descriptorBuilder, name, read, write)
 
 public fun <D : Device> DeviceSpec<D>.mutableMetaProperty(
-    descriptorBuilder: PropertyDescriptor.() -> Unit = {},
+    descriptorBuilder: PropertyDescriptorBuilder.() -> Unit = {},
     name: String? = null,
     read: suspend D.(propertyName: String) -> Meta,
     write: suspend D.(propertyName: String, value: Meta) -> Unit
diff --git a/controls-core/src/jsMain/kotlin/space/kscience/controls/spec/fromSpec.js.kt b/controls-core/src/jsMain/kotlin/space/kscience/controls/spec/fromSpec.js.kt
index cd77248..bf44a4e 100644
--- a/controls-core/src/jsMain/kotlin/space/kscience/controls/spec/fromSpec.js.kt
+++ b/controls-core/src/jsMain/kotlin/space/kscience/controls/spec/fromSpec.js.kt
@@ -1,9 +1,9 @@
 package space.kscience.controls.spec
 
-import space.kscience.controls.api.ActionDescriptor
-import space.kscience.controls.api.PropertyDescriptor
+import space.kscience.controls.api.ActionDescriptorBuilder
+import space.kscience.controls.api.PropertyDescriptorBuilder
 import kotlin.reflect.KProperty
 
-internal actual fun PropertyDescriptor.fromSpec(property: KProperty<*>){}
+internal actual fun PropertyDescriptorBuilder.fromSpec(property: KProperty<*>){}
 
-internal actual fun ActionDescriptor.fromSpec(property: KProperty<*>){}
\ No newline at end of file
+internal actual fun ActionDescriptorBuilder.fromSpec(property: KProperty<*>){}
\ No newline at end of file
diff --git a/controls-core/src/jvmMain/kotlin/space/kscience/controls/spec/fromSpec.jvm.kt b/controls-core/src/jvmMain/kotlin/space/kscience/controls/spec/fromSpec.jvm.kt
index cb64fc3..91406f2 100644
--- a/controls-core/src/jvmMain/kotlin/space/kscience/controls/spec/fromSpec.jvm.kt
+++ b/controls-core/src/jvmMain/kotlin/space/kscience/controls/spec/fromSpec.jvm.kt
@@ -1,18 +1,18 @@
 package space.kscience.controls.spec
 
-import space.kscience.controls.api.ActionDescriptor
-import space.kscience.controls.api.PropertyDescriptor
+import space.kscience.controls.api.ActionDescriptorBuilder
+import space.kscience.controls.api.PropertyDescriptorBuilder
 import space.kscience.dataforge.descriptors.Description
 import kotlin.reflect.KProperty
 import kotlin.reflect.full.findAnnotation
 
-internal actual fun PropertyDescriptor.fromSpec(property: KProperty<*>) {
+internal actual fun PropertyDescriptorBuilder.fromSpec(property: KProperty<*>) {
     property.findAnnotation<Description>()?.let {
         description = it.value
     }
 }
 
-internal actual fun ActionDescriptor.fromSpec(property: KProperty<*>){
+internal actual fun ActionDescriptorBuilder.fromSpec(property: KProperty<*>){
     property.findAnnotation<Description>()?.let {
         description = it.value
     }
diff --git a/controls-core/src/nativeMain/kotlin/space/kscience/controls/spec/fromSpec.native.kt b/controls-core/src/nativeMain/kotlin/space/kscience/controls/spec/fromSpec.native.kt
index 1d1ccc4..eeec224 100644
--- a/controls-core/src/nativeMain/kotlin/space/kscience/controls/spec/fromSpec.native.kt
+++ b/controls-core/src/nativeMain/kotlin/space/kscience/controls/spec/fromSpec.native.kt
@@ -1,9 +1,9 @@
 package space.kscience.controls.spec
 
-import space.kscience.controls.api.ActionDescriptor
-import space.kscience.controls.api.PropertyDescriptor
+import space.kscience.controls.api.ActionDescriptorBuilder
+import space.kscience.controls.api.PropertyDescriptorBuilder
 import kotlin.reflect.KProperty
 
-internal actual fun PropertyDescriptor.fromSpec(property: KProperty<*>) {}
+internal actual fun PropertyDescriptorBuilder.fromSpec(property: KProperty<*>) {}
 
-internal actual fun ActionDescriptor.fromSpec(property: KProperty<*>){}
\ No newline at end of file
+internal actual fun ActionDescriptorBuilder.fromSpec(property: KProperty<*>){}
\ No newline at end of file
diff --git a/controls-core/src/wasmJsMain/kotlin/fromSpec.wasm.kt b/controls-core/src/wasmJsMain/kotlin/fromSpec.wasm.kt
index cd77248..bf44a4e 100644
--- a/controls-core/src/wasmJsMain/kotlin/fromSpec.wasm.kt
+++ b/controls-core/src/wasmJsMain/kotlin/fromSpec.wasm.kt
@@ -1,9 +1,9 @@
 package space.kscience.controls.spec
 
-import space.kscience.controls.api.ActionDescriptor
-import space.kscience.controls.api.PropertyDescriptor
+import space.kscience.controls.api.ActionDescriptorBuilder
+import space.kscience.controls.api.PropertyDescriptorBuilder
 import kotlin.reflect.KProperty
 
-internal actual fun PropertyDescriptor.fromSpec(property: KProperty<*>){}
+internal actual fun PropertyDescriptorBuilder.fromSpec(property: KProperty<*>){}
 
-internal actual fun ActionDescriptor.fromSpec(property: KProperty<*>){}
\ No newline at end of file
+internal actual fun ActionDescriptorBuilder.fromSpec(property: KProperty<*>){}
\ No newline at end of file
diff --git a/demo/all-things/src/main/kotlin/space/kscience/controls/demo/DemoDevice.kt b/demo/all-things/src/main/kotlin/space/kscience/controls/demo/DemoDevice.kt
index 5cf1b28..1514eac 100644
--- a/demo/all-things/src/main/kotlin/space/kscience/controls/demo/DemoDevice.kt
+++ b/demo/all-things/src/main/kotlin/space/kscience/controls/demo/DemoDevice.kt
@@ -2,7 +2,6 @@ package space.kscience.controls.demo
 
 import kotlinx.coroutines.launch
 import space.kscience.controls.api.Device
-import space.kscience.controls.api.metaDescriptor
 import space.kscience.controls.spec.*
 import space.kscience.dataforge.context.Context
 import space.kscience.dataforge.context.Factory