diff --git a/src/main/java/com/atgenomix/seqslab/piper/plugin/api/Pipeline.java b/src/main/java/com/atgenomix/seqslab/piper/plugin/api/Pipeline.java
index 594d9e7..970f2fc 100644
--- a/src/main/java/com/atgenomix/seqslab/piper/plugin/api/Pipeline.java
+++ b/src/main/java/com/atgenomix/seqslab/piper/plugin/api/Pipeline.java
@@ -30,10 +30,14 @@
 public interface Pipeline {
 
     /**
-     * Get the settings of File inputs.
-     * @return A dictionary containing the FQN-value mappings.
+     * Get the settings of Task inputs.
      */
-    Map<String, PiperValue> getDatasets();
+    Map<String, PiperValue> getInputs();
+
+    /**
+     * Get the settings of Task outputs.
+     */
+    Map<String, PiperValue> getOutputs();
 
     /**
      * Get the settings of a pipeline task.
diff --git a/src/main/java/com/atgenomix/seqslab/piper/plugin/api/PipelineTask.java b/src/main/java/com/atgenomix/seqslab/piper/plugin/api/PipelineTask.java
index 067c1d4..0d68b65 100644
--- a/src/main/java/com/atgenomix/seqslab/piper/plugin/api/PipelineTask.java
+++ b/src/main/java/com/atgenomix/seqslab/piper/plugin/api/PipelineTask.java
@@ -18,6 +18,9 @@
 
 
 import com.atgenomix.seqslab.piper.tags.DeveloperApi;
+import com.google.gson.JsonObject;
+
+import java.util.List;
 
 /**
  * An interface represents the localization, computation, and delocalization workload processes
@@ -26,4 +29,10 @@
  */
 @DeveloperApi
 public interface PipelineTask {
+
+    /**
+     * Get the list of Operators applied on given input or output FQN.
+     * @return a list of JsonObject
+     */
+     public JsonObject[] getOperators();
 }
diff --git a/src/main/java/com/atgenomix/seqslab/piper/plugin/api/PiperContext.java b/src/main/java/com/atgenomix/seqslab/piper/plugin/api/PiperContext.java
index f307ed6..6791ed4 100644
--- a/src/main/java/com/atgenomix/seqslab/piper/plugin/api/PiperContext.java
+++ b/src/main/java/com/atgenomix/seqslab/piper/plugin/api/PiperContext.java
@@ -69,12 +69,21 @@ public Map<String, String> getConf() {
     }
 
     /**
-     * Obtain the dataset object value of an input variable identified by fully-qualified name.
+     * Obtain the piper value of an input variable identified by fully-qualified name.
      * @param fqn The fully-qualified name of an input variable, e.g. myworkflow.task.ref.
-     * @return The dataset object value or null if not found.
+     * @return The piper value or null if not found.
      */
-    public PiperValue getDataset(String fqn) {
-        return pipeline.getDatasets().get(fqn);
+    public PiperValue getInput(String fqn) {
+        return pipeline.getInputs().get(fqn);
+    }
+
+    /**
+     * Obtain the piper value of an output variable identified by fully-qualified name.
+     * @param fqn The fully-qualified name of an output variable, e.g. myworkflow.task.ref.
+     * @return The piper value or null if not found.
+     */
+    public PiperValue getOutput(String fqn) {
+        return pipeline.getOutputs().get(fqn);
     }
 
     /**