diff --git a/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/DataNode.kt b/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/DataNode.kt
index 4cc5aaf0..d7158dab 100644
--- a/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/DataNode.kt
+++ b/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/DataNode.kt
@@ -1,8 +1,6 @@
 package hep.dataforge.data
 
-import hep.dataforge.meta.Meta
-import hep.dataforge.meta.MetaRepr
-import hep.dataforge.meta.buildMeta
+import hep.dataforge.meta.*
 import hep.dataforge.names.*
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Job
@@ -18,20 +16,20 @@ sealed class DataItem<out T : Any> : MetaRepr {
     class Node<out T : Any>(val value: DataNode<T>) : DataItem<T>() {
         override val type: KClass<out T> get() = value.type
 
-        override fun toMeta(): Meta  = value.toMeta()
+        override fun toMeta(): Meta = value.toMeta()
     }
 
     class Leaf<out T : Any>(val value: Data<T>) : DataItem<T>() {
         override val type: KClass<out T> get() = value.type
 
-        override fun toMeta(): Meta  = value.toMeta()
+        override fun toMeta(): Meta = value.toMeta()
     }
 }
 
 /**
  * A tree-like data structure grouped into the node. All data inside the node must inherit its type
  */
-interface DataNode<out T : Any>: MetaRepr {
+interface DataNode<out T : Any> : MetaRepr {
 
     /**
      * The minimal common ancestor to all data in the node
@@ -41,7 +39,7 @@ interface DataNode<out T : Any>: MetaRepr {
     val items: Map<NameToken, DataItem<T>>
 
     override fun toMeta(): Meta = buildMeta {
-        "type" to (type.simpleName?:"undefined")
+        "type" to (type.simpleName ?: "undefined")
         "items" to {
             this@DataNode.items.forEach {
                 it.key.toString() to it.value.toMeta()
@@ -52,9 +50,12 @@ interface DataNode<out T : Any>: MetaRepr {
     companion object {
         const val TYPE = "dataNode"
 
-        fun <T : Any> build(type: KClass<out T>, block: DataTreeBuilder<T>.() -> Unit) =
+        operator fun <T : Any> invoke(type: KClass<out T>, block: DataTreeBuilder<T>.() -> Unit) =
             DataTreeBuilder(type).apply(block).build()
 
+        inline operator fun <reified T : Any> invoke(noinline block: DataTreeBuilder<T>.() -> Unit) =
+            DataTreeBuilder(T::class).apply(block).build()
+
         fun <T : Any> builder(type: KClass<out T>) = DataTreeBuilder(type)
     }
 }
@@ -142,7 +143,7 @@ private sealed class DataTreeBuilderItem<out T : Any> {
 class DataTreeBuilder<T : Any>(private val type: KClass<out T>) {
     private val map = HashMap<NameToken, DataTreeBuilderItem<T>>()
 
-    operator fun set(token: NameToken, node: DataTreeBuilder<T>) {
+    operator fun set(token: NameToken, node: DataTreeBuilder<out T>) {
         if (map.containsKey(token)) error("Tree entry with name $token is not empty")
         map[token] = DataTreeBuilderItem.Node(node)
     }
@@ -154,9 +155,9 @@ class DataTreeBuilder<T : Any>(private val type: KClass<out T>) {
 
     private fun buildNode(token: NameToken): DataTreeBuilder<T> {
         return if (!map.containsKey(token)) {
-            DataTreeBuilder<T>(type).also { map[token] = DataTreeBuilderItem.Node(it) }
+            DataTreeBuilder(type).also { map[token] = DataTreeBuilderItem.Node(it) }
         } else {
-            (map[token] as? DataTreeBuilderItem.Node ?: error("The node with name $token is occupied by leaf")).tree
+            (map[token] as? DataTreeBuilderItem.Node<T> ?: error("The node with name $token is occupied by leaf")).tree
         }
     }
 
@@ -176,7 +177,7 @@ class DataTreeBuilder<T : Any>(private val type: KClass<out T>) {
         }
     }
 
-    operator fun set(name: Name, node: DataTreeBuilder<T>) {
+    operator fun set(name: Name, node: DataTreeBuilder<out T>) {
         when (name.length) {
             0 -> error("Can't add data with empty name")
             1 -> set(name.first()!!, node)
@@ -206,7 +207,7 @@ class DataTreeBuilder<T : Any>(private val type: KClass<out T>) {
     /**
      * Build and append node
      */
-    infix fun String.to(block: DataTreeBuilder<T>.() -> Unit) = set(toName(), DataTreeBuilder<T>(type).apply(block))
+    infix fun String.to(block: DataTreeBuilder<out T>.() -> Unit) = set(toName(), DataTreeBuilder<T>(type).apply(block))
 
 
     fun update(node: DataNode<T>) {
@@ -227,6 +228,42 @@ class DataTreeBuilder<T : Any>(private val type: KClass<out T>) {
     }
 }
 
+fun <T : Any> DataTreeBuilder<T>.datum(name: Name, data: Data<T>) {
+    this[name] = data
+}
+
+fun <T : Any> DataTreeBuilder<T>.datum(name: String, data: Data<T>) {
+    this[name.toName()] = data
+}
+
+fun <T : Any> DataTreeBuilder<T>.static(name: Name, data: T, meta: Meta = EmptyMeta) {
+    this[name] = Data.static(data, meta)
+}
+
+fun <T : Any> DataTreeBuilder<T>.static(name: Name, data: T, block: MetaBuilder.() -> Unit = {}) {
+    this[name] = Data.static(data, buildMeta(block))
+}
+
+fun <T : Any> DataTreeBuilder<T>.static(name: String, data: T, block: MetaBuilder.() -> Unit = {}) {
+    this[name.toName()] = Data.static(data, buildMeta(block))
+}
+
+fun <T : Any> DataTreeBuilder<T>.node(name: Name, node: DataNode<T>) {
+    this[name] = node
+}
+
+fun <T : Any> DataTreeBuilder<T>.node(name: String, node: DataNode<T>) {
+    this[name.toName()] = node
+}
+
+inline fun <reified T : Any> DataTreeBuilder<T>.node(name: Name, noinline block: DataTreeBuilder<T>.() -> Unit) {
+    this[name] = DataNode(T::class, block)
+}
+
+inline fun <reified T : Any> DataTreeBuilder<T>.node(name: String, noinline block: DataTreeBuilder<T>.() -> Unit) {
+    this[name.toName()] = DataNode(T::class, block)
+}
+
 /**
  * Generate a mutable builder from this node. Node content is not changed
  */
@@ -234,7 +271,7 @@ fun <T : Any> DataNode<T>.builder(): DataTreeBuilder<T> = DataTreeBuilder(type).
     dataSequence().forEach { (name, data) -> this[name] = data }
 }
 
-fun <T : Any> DataNode<T>.filter(predicate: (Name, Data<T>) -> Boolean): DataNode<T> = DataNode.build(type) {
+fun <T : Any> DataNode<T>.filter(predicate: (Name, Data<T>) -> Boolean): DataNode<T> = DataNode.invoke(type) {
     dataSequence().forEach { (name, data) ->
         if (predicate(name, data)) {
             this[name] = data
diff --git a/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/JoinAction.kt b/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/JoinAction.kt
index 31a54a74..7ad4055e 100644
--- a/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/JoinAction.kt
+++ b/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/JoinAction.kt
@@ -74,14 +74,14 @@ class JoinGroupBuilder<T : Any, R : Any>(val actionMeta: Meta) {
  * The same rules as for KPipe
  */
 class JoinAction<T : Any, R : Any>(
-    val inputType: KClass<T>,
-    val outputType: KClass<R>,
+    val inputType: KClass<out T>,
+    val outputType: KClass<out R>,
     private val action: JoinGroupBuilder<T, R>.() -> Unit
 ) : Action<T, R> {
 
     override fun invoke(node: DataNode<T>, meta: Meta): DataNode<R> {
         node.ensureType(inputType)
-        return DataNode.build(outputType) {
+        return DataNode.invoke(outputType) {
             JoinGroupBuilder<T, R>(meta).apply(action).buildGroups(node).forEach { group ->
 
                 val laminate = Laminate(group.meta, meta)
diff --git a/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/PipeAction.kt b/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/PipeAction.kt
index 59162179..91a204d8 100644
--- a/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/PipeAction.kt
+++ b/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/PipeAction.kt
@@ -22,16 +22,16 @@ class PipeBuilder<T, R>(var name: Name, var meta: MetaBuilder) {
 }
 
 
-class PipeAction<T : Any, R : Any>(
-    val inputType: KClass<T>,
-    val outputType: KClass<R>,
+class PipeAction<T : Any, out R : Any>(
+    val inputType: KClass<out T>,
+    val outputType: KClass<out R>,
     private val block: PipeBuilder<T, R>.() -> Unit
 ) : Action<T, R> {
 
     override fun invoke(node: DataNode<T>, meta: Meta): DataNode<R> {
         node.ensureType(inputType)
 
-        return DataNode.build(outputType) {
+        return DataNode.invoke(outputType) {
             node.dataSequence().forEach { (name, data) ->
                 //merging data meta with action meta (data meta is primary)
                 val oldMeta = meta.builder().apply { update(data.meta) }
@@ -53,7 +53,7 @@ class PipeAction<T : Any, R : Any>(
 
 inline fun <reified T : Any, reified R : Any> DataNode<T>.pipe(
     meta: Meta,
-    noinline action: PipeBuilder<T, R>.() -> Unit
+    noinline action: PipeBuilder<in T, out R>.() -> Unit
 ): DataNode<R> = PipeAction(T::class, R::class, action).invoke(this, meta)
 
 
diff --git a/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/SplitAction.kt b/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/SplitAction.kt
index 1e7e6c7c..637baeeb 100644
--- a/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/SplitAction.kt
+++ b/dataforge-data/src/commonMain/kotlin/hep/dataforge/data/SplitAction.kt
@@ -33,15 +33,15 @@ class SplitBuilder<T : Any, R : Any>(val name: Name, val meta: Meta) {
 }
 
 class SplitAction<T : Any, R : Any>(
-    val inputType: KClass<T>,
-    val outputType: KClass<R>,
+    val inputType: KClass<out T>,
+    val outputType: KClass<out R>,
     private val action: SplitBuilder<T, R>.() -> Unit
 ) : Action<T, R> {
 
     override fun invoke(node: DataNode<T>, meta: Meta): DataNode<R> {
         node.ensureType(inputType)
 
-        return DataNode.build(outputType) {
+        return DataNode.invoke(outputType) {
             node.dataSequence().forEach { (name, data) ->
 
                 val laminate = Laminate(data.meta, meta)
diff --git a/dataforge-data/src/jvmMain/kotlin/hep/dataforge/data/TypeFilteredDataNode.kt b/dataforge-data/src/jvmMain/kotlin/hep/dataforge/data/TypeFilteredDataNode.kt
index 5e90c4ed..d24de964 100644
--- a/dataforge-data/src/jvmMain/kotlin/hep/dataforge/data/TypeFilteredDataNode.kt
+++ b/dataforge-data/src/jvmMain/kotlin/hep/dataforge/data/TypeFilteredDataNode.kt
@@ -12,12 +12,12 @@ class TypeFilteredDataNode<out T : Any>(val origin: DataNode<*>, override val ty
         origin.items.mapNotNull { (key, item) ->
             when (item) {
                 is DataItem.Leaf -> {
-                    (item.value.withType(type))?.let {
+                    (item.value.filterIsInstance(type))?.let {
                         key to DataItem.Leaf(it)
                     }
                 }
                 is DataItem.Node -> {
-                    key to DataItem.Node(item.value.withType(type))
+                    key to DataItem.Node(item.value.filterIsInstance(type))
                 }
             }
         }.associate { it }
diff --git a/dataforge-data/src/jvmMain/kotlin/hep/dataforge/data/dataJVM.kt b/dataforge-data/src/jvmMain/kotlin/hep/dataforge/data/dataJVM.kt
index 395f92b1..5b5507b2 100644
--- a/dataforge-data/src/jvmMain/kotlin/hep/dataforge/data/dataJVM.kt
+++ b/dataforge-data/src/jvmMain/kotlin/hep/dataforge/data/dataJVM.kt
@@ -22,18 +22,18 @@ actual fun <R : Any> Data<*>.canCast(type: KClass<out R>): Boolean =
 /**
  * Cast the node to given type if the cast is possible or return null
  */
-fun <R : Any> Data<*>.withType(type: KClass<out R>): Data<R>? =
+fun <R : Any> Data<*>.filterIsInstance(type: KClass<out R>): Data<R>? =
     if (canCast(type)) cast(type) else null
 
 /**
  * Filter a node by data and node type. Resulting node and its subnodes is guaranteed to have border type [type],
  * but could contain empty nodes
  */
-fun <R : Any> DataNode<*>.withType(type: KClass<out R>): DataNode<R> {
+fun <R : Any> DataNode<*>.filterIsInstance(type: KClass<out R>): DataNode<R> {
     return if (canCast(type)) {
         cast(type)
     } else if (this is TypeFilteredDataNode) {
-        origin.withType(type)
+        origin.filterIsInstance(type)
     } else {
         TypeFilteredDataNode(this, type)
     }
@@ -42,10 +42,10 @@ fun <R : Any> DataNode<*>.withType(type: KClass<out R>): DataNode<R> {
 /**
  * Filter all elements of given data item that could be cast to given type. If no elements are available, return null.
  */
-fun <R : Any> DataItem<*>?.withType(type: KClass<out R>): DataItem<R>? = when (this) {
+fun <R : Any> DataItem<*>?.filterIsInstance(type: KClass<out R>): DataItem<R>? = when (this) {
     null -> null
-    is DataItem.Node -> DataItem.Node(this.value.withType(type))
-    is DataItem.Leaf -> this.value.withType(type)?.let { DataItem.Leaf(it) }
+    is DataItem.Node -> DataItem.Node(this.value.filterIsInstance(type))
+    is DataItem.Leaf -> this.value.filterIsInstance(type)?.let { DataItem.Leaf(it) }
 }
 
-inline fun <reified R : Any> DataItem<*>?.withType(): DataItem<R>? = this@withType.withType(R::class)
\ No newline at end of file
+inline fun <reified R : Any> DataItem<*>?.filterIsInstance(): DataItem<R>? = this@filterIsInstance.filterIsInstance(R::class)
\ No newline at end of file
diff --git a/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/Dependency.kt b/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/Dependency.kt
index 1e1a9c3f..1f184095 100644
--- a/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/Dependency.kt
+++ b/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/Dependency.kt
@@ -21,7 +21,7 @@ class DataDependency(val filter: DataFilter, val placement: Name = EmptyName) :
         return if (placement.isEmpty()) {
             result
         } else {
-            DataNode.build(Any::class) { this[placement] = result }
+            DataNode.invoke(Any::class) { this[placement] = result }
         }
     }
 
@@ -35,7 +35,7 @@ class AllDataDependency(val placement: Name = EmptyName) : Dependency() {
     override fun apply(workspace: Workspace): DataNode<Any> = if (placement.isEmpty()) {
         workspace.data
     } else {
-        DataNode.build(Any::class) { this[placement] = workspace.data }
+        DataNode.invoke(Any::class) { this[placement] = workspace.data }
     }
 
     override fun toMeta() = buildMeta {
@@ -44,22 +44,25 @@ class AllDataDependency(val placement: Name = EmptyName) : Dependency() {
     }
 }
 
-abstract class TaskDependency(val meta: Meta, val placement: Name = EmptyName) : Dependency() {
-    abstract fun resolveTask(workspace: Workspace): Task<*>
+abstract class TaskDependency<out T : Any>(
+    val meta: Meta,
+    val placement: Name = EmptyName
+) : Dependency() {
+    abstract fun resolveTask(workspace: Workspace): Task<T>
 
     /**
      * A name of the dependency for logging and serialization
      */
     abstract val name: Name
 
-    override fun apply(workspace: Workspace): DataNode<Any> {
+    override fun apply(workspace: Workspace): DataNode<T> {
         val task = resolveTask(workspace)
         if (task.isTerminal) TODO("Support terminal task")
         val result = workspace.run(task, meta)
         return if (placement.isEmpty()) {
             result
         } else {
-            DataNode.build(Any::class) { this[placement] = result }
+            DataNode(task.type) { this[placement] = result }
         }
     }
 
@@ -70,8 +73,12 @@ abstract class TaskDependency(val meta: Meta, val placement: Name = EmptyName) :
     }
 }
 
-class DirectTaskDependency(val task: Task<*>, meta: Meta, placement: Name) : TaskDependency(meta, placement) {
-    override fun resolveTask(workspace: Workspace): Task<*> = task
+class DirectTaskDependency<T : Any>(
+    val task: Task<T>,
+    meta: Meta,
+    placement: Name
+) : TaskDependency<T>(meta, placement) {
+    override fun resolveTask(workspace: Workspace): Task<T> = task
 
     override val name: Name get() = DIRECT_TASK_NAME + task.name
 
@@ -80,7 +87,7 @@ class DirectTaskDependency(val task: Task<*>, meta: Meta, placement: Name) : Tas
     }
 }
 
-class WorkspaceTaskDependency(override val name: Name, meta: Meta, placement: Name) : TaskDependency(meta, placement) {
+class WorkspaceTaskDependency(override val name: Name, meta: Meta, placement: Name) : TaskDependency<Any>(meta, placement) {
     override fun resolveTask(workspace: Workspace): Task<*> =
         workspace.tasks[name] ?: error("Task with name $name is not found in the workspace")
 }
\ No newline at end of file
diff --git a/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/GenericTask.kt b/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/GenericTask.kt
index a46862a0..408f1745 100644
--- a/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/GenericTask.kt
+++ b/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/GenericTask.kt
@@ -20,7 +20,7 @@ class GenericTask<R : Any>(
 ) : Task<R> {
 
     private fun gather(workspace: Workspace, model: TaskModel): DataNode<Any> {
-        return DataNode.build(Any::class) {
+        return DataNode.invoke(Any::class) {
             model.dependencies.forEach { dep ->
                 update(dep.apply(workspace))
             }
diff --git a/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/TaskBuilder.kt b/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/TaskBuilder.kt
index 41b90681..bdacb711 100644
--- a/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/TaskBuilder.kt
+++ b/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/TaskBuilder.kt
@@ -13,7 +13,7 @@ import hep.dataforge.names.toName
 import kotlin.reflect.KClass
 
 @TaskBuildScope
-class TaskBuilder(val name: String) {
+class TaskBuilder<R : Any>(val name: String, val type: KClass<out R>) {
     private var modelTransform: TaskModelBuilder.(Meta) -> Unit = { allData() }
     var descriptor: NodeDescriptor? = null
     private val dataTransforms: MutableList<DataTransformation> = ArrayList()
@@ -21,12 +21,12 @@ class TaskBuilder(val name: String) {
     /**
      * TODO will look better as extension class
      */
-    private class DataTransformation(
+    private inner class DataTransformation(
         val from: String = "",
         val to: String = "",
-        val transform: (Context, TaskModel, DataNode<Any>) -> DataNode<Any>
+        val transform: (Context, TaskModel, DataNode<Any>) -> DataNode<R>
     ) {
-        operator fun invoke(workspace: Workspace, model: TaskModel, node: DataNode<Any>): DataNode<Any>? {
+        operator fun invoke(workspace: Workspace, model: TaskModel, node: DataNode<Any>): DataNode<R>? {
             val localData = if (from.isEmpty()) {
                 node
             } else {
@@ -46,9 +46,9 @@ class TaskBuilder(val name: String) {
     fun rawTransform(
         from: String = "",
         to: String = "",
-        block: TaskEnv.(DataNode<*>) -> DataNode<*>
+        block: TaskEnv.(DataNode<*>) -> DataNode<R>
     ) {
-        dataTransforms += DataTransformation(from, to){context, model, data->
+        dataTransforms += DataTransformation(from, to) { context, model, data ->
             val env = TaskEnv(EmptyName, model.meta, context)
             env.block(data)
         }
@@ -58,7 +58,7 @@ class TaskBuilder(val name: String) {
         inputType: KClass<out T>,
         from: String = "",
         to: String = "",
-        block: TaskEnv.(DataNode<T>) -> DataNode<Any>
+        block: TaskEnv.(DataNode<T>) -> DataNode<R>
     ) {
         dataTransforms += DataTransformation(from, to) { context, model, data ->
             data.ensureType(inputType)
@@ -70,7 +70,7 @@ class TaskBuilder(val name: String) {
     inline fun <reified T : Any> transform(
         from: String = "",
         to: String = "",
-        noinline block: TaskEnv.(DataNode<T>) -> DataNode<Any>
+        noinline block: TaskEnv.(DataNode<T>) -> DataNode<R>
     ) {
         transform(T::class, from, to, block)
     }
@@ -78,7 +78,7 @@ class TaskBuilder(val name: String) {
     /**
      * Perform given action on data elements in `from` node in input and put the result to `to` node
      */
-    inline fun <reified T : Any, reified R : Any> action(
+    inline fun <reified T : Any> action(
         from: String = "",
         to: String = "",
         crossinline block: TaskEnv.() -> Action<T, R>
@@ -93,7 +93,7 @@ class TaskBuilder(val name: String) {
     /**
      * A customized pipe action with ability to change meta and name
      */
-    inline fun <reified T : Any, reified R : Any> customPipe(
+    inline fun <reified T : Any> customPipe(
         from: String = "",
         to: String = "",
         crossinline block: PipeBuilder<T, R>.(TaskEnv) -> Unit
@@ -101,7 +101,7 @@ class TaskBuilder(val name: String) {
         action(from, to) {
             PipeAction(
                 inputType = T::class,
-                outputType = R::class
+                outputType = type
             ) { block(this@action) }
         }
     }
@@ -109,7 +109,7 @@ class TaskBuilder(val name: String) {
     /**
      * A simple pipe action without changing meta or name
      */
-    inline fun <reified T : Any, reified R : Any> pipe(
+    inline fun <reified T : Any> pipe(
         from: String = "",
         to: String = "",
         crossinline block: suspend TaskEnv.(T) -> R
@@ -117,7 +117,7 @@ class TaskBuilder(val name: String) {
         action(from, to) {
             PipeAction(
                 inputType = T::class,
-                outputType = R::class
+                outputType = type
             ) {
                 //TODO automatically append task meta
                 result = { data ->
@@ -130,7 +130,7 @@ class TaskBuilder(val name: String) {
     /**
      * Join elements in gathered data by multiple groups
      */
-    inline fun <reified T : Any, reified R : Any> joinByGroup(
+    inline fun <reified T : Any> joinByGroup(
         from: String = "",
         to: String = "",
         crossinline block: JoinGroupBuilder<T, R>.(TaskEnv) -> Unit
@@ -138,7 +138,7 @@ class TaskBuilder(val name: String) {
         action(from, to) {
             JoinAction(
                 inputType = T::class,
-                outputType = R::class
+                outputType = type
             ) { block(this@action) }
         }
     }
@@ -146,7 +146,7 @@ class TaskBuilder(val name: String) {
     /**
      * Join all elemlents in gathered data matching input type
      */
-    inline fun <reified T : Any, reified R : Any> join(
+    inline fun <reified T : Any> join(
         from: String = "",
         to: String = "",
         crossinline block: suspend TaskEnv.(Map<Name, T>) -> R
@@ -154,7 +154,7 @@ class TaskBuilder(val name: String) {
         action(from, to) {
             JoinAction(
                 inputType = T::class,
-                outputType = R::class,
+                outputType = type,
                 action = {
                     result(
                         actionMeta[TaskModel.MODEL_TARGET_KEY]?.string ?: "@anonymous"
@@ -169,7 +169,7 @@ class TaskBuilder(val name: String) {
     /**
      * Split each element in gathered data into fixed number of fragments
      */
-    inline fun <reified T : Any, reified R : Any> split(
+    inline fun <reified T : Any> split(
         from: String = "",
         to: String = "",
         crossinline block: SplitBuilder<T, R>.(TaskEnv) -> Unit
@@ -177,7 +177,7 @@ class TaskBuilder(val name: String) {
         action(from, to) {
             SplitAction(
                 inputType = T::class,
-                outputType = R::class
+                outputType = type
             ) { block(this@action) }
         }
     }
@@ -189,22 +189,23 @@ class TaskBuilder(val name: String) {
         this.descriptor = NodeDescriptor.build(transform)
     }
 
-    internal fun build(): GenericTask<Any> =
+    internal fun build(): GenericTask<R> =
         GenericTask(
             name.asName(),
-            Any::class,
+            type,
             descriptor ?: NodeDescriptor.empty(),
             modelTransform
         ) {
             val workspace = this
-            { data ->
+            return@GenericTask { data ->
                 val model = this
                 if (dataTransforms.isEmpty()) {
                     //return data node as is
                     logger.warn { "No transformation present, returning input data" }
-                    data
+                    data.ensureType(type)
+                    data.cast(type)
                 } else {
-                    val builder = DataTreeBuilder(Any::class)
+                    val builder = DataTreeBuilder(type)
                     dataTransforms.forEach { transformation ->
                         val res = transformation(workspace, model, data)
                         if (res != null) {
@@ -221,12 +222,13 @@ class TaskBuilder(val name: String) {
         }
 }
 
-fun Workspace.Companion.task(name: String, builder: TaskBuilder.() -> Unit): GenericTask<Any> {
-    return TaskBuilder(name).apply(builder).build()
+fun <T : Any> Workspace.Companion.task(
+    name: String,
+    type: KClass<out T>,
+    builder: TaskBuilder<T>.() -> Unit
+): GenericTask<T> {
+    return TaskBuilder(name, type).apply(builder).build()
 }
 
-fun WorkspaceBuilder.task(name: String, builder: TaskBuilder.() -> Unit) {
-    task(TaskBuilder(name).apply(builder).build())
-}
 
 //TODO add delegates to build gradle-like tasks
\ No newline at end of file
diff --git a/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/TaskModel.kt b/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/TaskModel.kt
index e7443807..f9562438 100644
--- a/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/TaskModel.kt
+++ b/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/TaskModel.kt
@@ -36,7 +36,7 @@ data class TaskModel(
         "meta" to meta
         "dependsOn" to {
             val dataDependencies = dependencies.filterIsInstance<DataDependency>()
-            val taskDependencies = dependencies.filterIsInstance<TaskDependency>()
+            val taskDependencies = dependencies.filterIsInstance<TaskDependency<*>>()
             setIndexed("data".toName(), dataDependencies.map { it.toMeta() })
             setIndexed("task".toName(), taskDependencies.map { it.toMeta() }) { taskDependencies[it].name.toString() }
             //TODO ensure all dependencies are listed
diff --git a/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/WorkspaceBuilder.kt b/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/WorkspaceBuilder.kt
index 999ee50c..6bc4900a 100644
--- a/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/WorkspaceBuilder.kt
+++ b/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/WorkspaceBuilder.kt
@@ -2,12 +2,14 @@ package hep.dataforge.workspace
 
 import hep.dataforge.context.Context
 import hep.dataforge.context.ContextBuilder
-import hep.dataforge.data.Data
 import hep.dataforge.data.DataNode
 import hep.dataforge.data.DataTreeBuilder
 import hep.dataforge.meta.*
+import hep.dataforge.names.EmptyName
 import hep.dataforge.names.Name
-import hep.dataforge.names.toName
+import hep.dataforge.names.isEmpty
+import kotlin.jvm.JvmName
+import kotlin.reflect.KClass
 
 @TaskBuildScope
 interface WorkspaceBuilder {
@@ -28,32 +30,26 @@ fun WorkspaceBuilder.context(name: String = "WORKSPACE", block: ContextBuilder.(
     context = ContextBuilder(name, parentContext).apply(block).build()
 }
 
-fun WorkspaceBuilder.data(name: Name, data: Data<Any>) {
-    this.data[name] = data
+inline fun <reified T : Any> WorkspaceBuilder.data(
+    name: Name = EmptyName,
+    noinline block: DataTreeBuilder<T>.() -> Unit
+): DataNode<T> {
+    val node = DataTreeBuilder(T::class).apply(block)
+    if (name.isEmpty()) {
+        @Suppress("UNCHECKED_CAST")
+        data = node as DataTreeBuilder<Any>
+    } else {
+        data[name] = node
+    }
+    return node.build()
 }
 
-fun WorkspaceBuilder.data(name: String, data: Data<Any>) = data(name.toName(), data)
+@JvmName("rawData")
+fun WorkspaceBuilder.data(
+    name: Name = EmptyName,
+    block: DataTreeBuilder<Any>.() -> Unit
+): DataNode<Any> = data<Any>(name, block)
 
-fun WorkspaceBuilder.static(name: Name, data: Any, meta: Meta = EmptyMeta) =
-    data(name, Data.static(data, meta))
-
-fun WorkspaceBuilder.static(name: Name, data: Any, block: MetaBuilder.() -> Unit = {}) =
-    data(name, Data.static(data, buildMeta(block)))
-
-fun WorkspaceBuilder.static(name: String, data: Any, block: MetaBuilder.() -> Unit = {}) =
-    data(name, Data.static(data, buildMeta(block)))
-
-fun WorkspaceBuilder.data(name: Name, node: DataNode<Any>) {
-    this.data[name] = node
-}
-
-fun WorkspaceBuilder.data(name: String, node: DataNode<Any>) = data(name.toName(), node)
-
-fun WorkspaceBuilder.data(name: Name, block: DataTreeBuilder<Any>.() -> Unit) {
-    this.data[name] = DataNode.build(Any::class, block)
-}
-
-fun WorkspaceBuilder.data(name: String, block: DataTreeBuilder<Any>.() -> Unit) = data(name.toName(), block)
 
 fun WorkspaceBuilder.target(name: String, block: MetaBuilder.() -> Unit) {
     targets[name] = buildMeta(block).seal()
@@ -70,17 +66,31 @@ fun WorkspaceBuilder.target(name: String, base: String, block: MetaBuilder.() ->
         .seal()
 }
 
-fun WorkspaceBuilder.task(task: Task<Any>) {
-    this.tasks.add(task)
+fun <T : Any> WorkspaceBuilder.task(
+    name: String,
+    type: KClass<out T>,
+    builder: TaskBuilder<T>.() -> Unit
+): Task<T> {
+    return TaskBuilder(name, type).apply(builder).build().also { tasks.add(it) }
 }
 
+inline fun <reified T : Any> WorkspaceBuilder.task(
+    name: String,
+    noinline builder: TaskBuilder<T>.() -> Unit
+): Task<T> = task(name, T::class, builder)
+
+@JvmName("rawTask")
+fun WorkspaceBuilder.task(
+    name: String,
+    builder: TaskBuilder<Any>.() -> Unit
+): Task<Any> = task(name, Any::class, builder)
 
 /**
  * A builder for a simple workspace
  */
 class SimpleWorkspaceBuilder(override val parentContext: Context) : WorkspaceBuilder {
     override var context: Context = parentContext
-    override var data = DataTreeBuilder(Any::class)
+    override var data: DataTreeBuilder<Any> = DataTreeBuilder(Any::class)
     override var tasks: MutableSet<Task<Any>> = HashSet()
     override var targets: MutableMap<String, Meta> = HashMap()
 
diff --git a/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/taskTemplates.kt b/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/taskTemplates.kt
index ab282015..a2602da3 100644
--- a/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/taskTemplates.kt
+++ b/dataforge-workspace/src/commonMain/kotlin/hep/dataforge/workspace/taskTemplates.kt
@@ -1,5 +1,5 @@
 package hep.dataforge.workspace
 
 //fun <T1: Any, T2: Any, R: Any> TaskBuilder.zip(
-//    val firstNo
-//) = rawTransform {  }
\ No newline at end of file
+////    val firstNo
+////) = rawTransform {  }
\ No newline at end of file
diff --git a/dataforge-workspace/src/jvmTest/kotlin/hep/dataforge/workspace/SimpleWorkspaceTest.kt b/dataforge-workspace/src/jvmTest/kotlin/hep/dataforge/workspace/SimpleWorkspaceTest.kt
index 95233251..2adc27b0 100644
--- a/dataforge-workspace/src/jvmTest/kotlin/hep/dataforge/workspace/SimpleWorkspaceTest.kt
+++ b/dataforge-workspace/src/jvmTest/kotlin/hep/dataforge/workspace/SimpleWorkspaceTest.kt
@@ -5,7 +5,7 @@ import hep.dataforge.data.*
 import hep.dataforge.meta.boolean
 import hep.dataforge.meta.get
 import hep.dataforge.names.asName
-import kotlin.test.Test
+import org.junit.Test
 import kotlin.test.assertEquals
 import kotlin.test.assertTrue
 
@@ -14,8 +14,8 @@ class SimpleWorkspaceTest {
     val testPlugin = object : WorkspacePlugin() {
         override val tag: PluginTag = PluginTag("test")
 
-        val contextTask = Workspace.task("test") {
-            pipe<Any, Unit> {
+        val contextTask = Workspace.task("test", Any::class) {
+            pipe<Any> {
                 context.logger.info { "Test: $it" }
             }
         }
@@ -28,8 +28,10 @@ class SimpleWorkspaceTest {
             plugin(testPlugin)
         }
 
-        repeat(100) {
-            static("myData[$it]", it)
+        data {
+            repeat(100) {
+                static("myData[$it]", it)
+            }
         }
 
 
@@ -37,7 +39,7 @@ class SimpleWorkspaceTest {
             model {
                 allData()
             }
-            pipe<Int, Int> { data ->
+            pipe<Int> { data ->
                 if (meta["testFlag"].boolean == true) {
                     println("flag")
                 }
@@ -50,7 +52,7 @@ class SimpleWorkspaceTest {
             model {
                 allData()
             }
-            pipe<Int, Int> { data ->
+            pipe<Int> { data ->
                 context.logger.info { "Starting linear on $data" }
                 data * 2 + 1
             }
@@ -62,16 +64,16 @@ class SimpleWorkspaceTest {
                 dependsOn("linear", placement = "linear".asName())
             }
             transform<Any> { data ->
-                val squareNode = data["square"].withType<Int>().node!!
-                val linearNode = data["linear"].withType<Int>().node!!
-                return@transform DataNode.build(Int::class) {
+                val squareNode = data["square"].filterIsInstance<Int>().node!!
+                val linearNode = data["linear"].filterIsInstance<Int>().node!!
+                return@transform DataNode(Int::class) {
                     squareNode.dataSequence().forEach { (name, _) ->
-                        val newData = Data{
+                        val newData = Data {
                             val squareValue = squareNode[name].data!!.get()
                             val linearValue = linearNode[name].data!!.get()
-                            squareValue+linearValue
+                            squareValue + linearValue
                         }
-                        set(name,newData)
+                        set(name, newData)
                     }
                 }
             }
@@ -81,17 +83,17 @@ class SimpleWorkspaceTest {
             model {
                 dependsOn("square")
             }
-            join<Int, Int> { data ->
+            join<Int> { data ->
                 context.logger.info { "Starting sum" }
                 data.values.sum()
             }
         }
 
-        task("average") {
+        task<Double>("average") {
             model {
                 allData()
             }
-            joinByGroup<Int, Double> { env ->
+            joinByGroup<Int> { env ->
                 group("even", filter = { name, _ -> name.toString().toInt() % 2 == 0 }) {
                     result { data ->
                         env.context.logger.info { "Starting even" }
@@ -111,7 +113,7 @@ class SimpleWorkspaceTest {
             model {
                 dependsOn("average")
             }
-            join<Double, Double> { data ->
+            join<Double> { data ->
                 data["even"]!! - data["odd"]!!
             }
         }
@@ -140,7 +142,7 @@ class SimpleWorkspaceTest {
     }
 
     @Test
-    fun testFullSquare(){
+    fun testFullSquare() {
         val node = workspace.run("fullsquare")
         println(node.toMeta())
     }