diff --git a/apps/workflow/api/src/main/java/org/onosproject/workflow/api/DataModelTree.java b/apps/workflow/api/src/main/java/org/onosproject/workflow/api/DataModelTree.java
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+++ b/apps/workflow/api/src/main/java/org/onosproject/workflow/api/DataModelTree.java
@@ -0,0 +1,63 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.workflow.api;
+
+/**
+ * Interface for data model tree.
+ */
+public interface DataModelTree {
+
+    /**
+     * Data model tree node type (map or array).
+     */
+    enum Nodetype {
+
+        /**
+         * Map type data model tree node.
+         */
+        MAP,
+
+        /**
+         * Array type data model tree node.
+         */
+        ARRAY
+    }
+
+    /**
+     * Returns subtree on the path.
+     * @param path data model tree path
+     * @return subtree on the path
+     */
+    DataModelTree subtree(String path);
+
+    /**
+     * Attaches subtree on the path.
+     * @param path data model tree path where subtree will be attached
+     * @param tree subtree to be attached
+     * @throws WorkflowException workflow exception
+     */
+    void attach(String path, DataModelTree tree) throws WorkflowException;
+
+    /**
+     * Allocates leaf node on the path.
+     * @param path data model tree path where new leaf node will be allocated
+     * @param leaftype leaf node type
+     * @return data model tree
+     * @throws WorkflowException workflow exception
+     */
+    DataModelTree alloc(String path, Nodetype leaftype) throws WorkflowException;
+}
+