diff --git a/common/src/main/java/org/implab/gradle/common/ProjectMixin.java b/common/src/main/java/org/implab/gradle/common/ProjectMixin.java
--- a/common/src/main/java/org/implab/gradle/common/ProjectMixin.java
+++ b/common/src/main/java/org/implab/gradle/common/ProjectMixin.java
@@ -10,8 +10,8 @@ import org.gradle.api.Task;
 import org.gradle.api.artifacts.Configuration;
 import org.gradle.api.file.Directory;
 import org.gradle.api.tasks.TaskContainer;
+import org.gradle.api.tasks.TaskProvider;
 import org.implab.gradle.common.dsl.TaskGroup;
-import org.implab.gradle.common.dsl.TaskSpec;
 import org.implab.gradle.common.dsl.TasksMixin;
 import org.implab.gradle.common.utils.ExtraProps;
 
@@ -21,9 +21,8 @@ public interface ProjectMixin extends Ta
     Project getProject();
 
     @Override
-    default <T extends Task> TaskSpec<T> task(String name, Class<T> clazz) {
-        var provider = getProject().getTasks().register(name, clazz);
-        return new TaskSpec<>(provider);
+    default <T extends Task> TaskProvider<T> task(String name, Class<T> clazz) {
+        return getProject().getTasks().register(name, clazz);
     }
 
     /** Creates a new task group */
diff --git a/common/src/main/java/org/implab/gradle/common/dsl/TaskGroup.java b/common/src/main/java/org/implab/gradle/common/dsl/TaskGroup.java
--- a/common/src/main/java/org/implab/gradle/common/dsl/TaskGroup.java
+++ b/common/src/main/java/org/implab/gradle/common/dsl/TaskGroup.java
@@ -4,6 +4,7 @@ import java.util.Objects;
 
 import org.gradle.api.Task;
 import org.gradle.api.tasks.TaskContainer;
+import org.gradle.api.tasks.TaskProvider;
 
 public abstract class TaskGroup implements TasksMixin {
     private final String groupName;
@@ -16,10 +17,10 @@ public abstract class TaskGroup implemen
     }
 
     @Override
-    public <T extends Task> TaskSpec<T> task(String taskName, Class<T> clazz) {
+    public <T extends Task> TaskProvider<T> task(String taskName, Class<T> clazz) {
         var provider = tasks().register(taskName, clazz);
         provider.configure(t -> t.setGroup(groupName));
-        return new TaskSpec<>(provider);
+        return provider;
     }
 
 }
diff --git a/common/src/main/java/org/implab/gradle/common/dsl/TasksMixin.java b/common/src/main/java/org/implab/gradle/common/dsl/TasksMixin.java
--- a/common/src/main/java/org/implab/gradle/common/dsl/TasksMixin.java
+++ b/common/src/main/java/org/implab/gradle/common/dsl/TasksMixin.java
@@ -1,12 +1,13 @@
 package org.implab.gradle.common.dsl;
 
 import org.gradle.api.Task;
+import org.gradle.api.tasks.TaskProvider;
 
 public interface TasksMixin {
 
-    default TaskSpec<Task> task(String name) {
+    default TaskProvider<Task> task(String name) {
         return task(name, Task.class);
     }
 
-    <T extends Task> TaskSpec<T> task(String name, Class<T> clazz);
+    <T extends Task> TaskProvider<T> task(String name, Class<T> clazz);
 }
diff --git a/common/src/main/java/org/implab/gradle/common/utils/Closures.java b/common/src/main/java/org/implab/gradle/common/utils/Closures.java
new file mode 100644
--- /dev/null
+++ b/common/src/main/java/org/implab/gradle/common/utils/Closures.java
@@ -0,0 +1,24 @@
+package org.implab.gradle.common.utils;
+
+import groovy.lang.Closure;
+
+import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.gradle.api.Action;
+
+@NonNullByDefault
+public final class Closures {
+    private Closures() {
+    }
+
+    public static <T> Action<T> action(Closure<?> closure) {
+        return arg -> {
+            closure.setDelegate(arg);
+            closure.call(arg);
+        };
+    }
+
+    public static void apply(Closure<?> action, Object target) {
+        action.setDelegate(target);
+        action.call(target);
+    }
+}
diff --git a/common/src/main/java/org/implab/gradle/common/utils/ObjectsMixin.java b/common/src/main/java/org/implab/gradle/common/utils/ObjectsMixin.java
--- a/common/src/main/java/org/implab/gradle/common/utils/ObjectsMixin.java
+++ b/common/src/main/java/org/implab/gradle/common/utils/ObjectsMixin.java
@@ -5,6 +5,7 @@ import java.util.function.Supplier;
 import javax.inject.Inject;
 
 import org.gradle.api.NamedDomainObjectContainer;
+import org.gradle.api.NamedDomainObjectFactory;
 import org.gradle.api.model.ObjectFactory;
 import org.gradle.api.provider.Provider;
 import org.gradle.api.provider.ProviderFactory;
@@ -37,4 +38,8 @@ public interface ObjectsMixin {
     default <T> NamedDomainObjectContainer<T> newContainer(Class<T> clazz) {
         return getObjects().domainObjectContainer(clazz);
     }
+
+    default <T> NamedDomainObjectContainer<T> newContainer(Class<T> clazz, NamedDomainObjectFactory<T> factory) {
+        return getObjects().domainObjectContainer(clazz, factory);
+    }
 }