diff --git a/core/src/main/java/com/google/bitcoin/core/GetDataMessage.java b/core/src/main/java/com/google/bitcoin/core/GetDataMessage.java
index 2f657637..55f74385 100644
--- a/core/src/main/java/com/google/bitcoin/core/GetDataMessage.java
+++ b/core/src/main/java/com/google/bitcoin/core/GetDataMessage.java
@@ -47,4 +47,12 @@ public class GetDataMessage extends ListMessage {
     public GetDataMessage(NetworkParameters params) {
         super(params);
     }
+
+    public void addTransaction(Sha256Hash hash) {
+        addItem(new InventoryItem(InventoryItem.Type.Transaction, hash));
+    }
+
+    public void addBlock(Sha256Hash hash) {
+        addItem(new InventoryItem(InventoryItem.Type.Block, hash));
+    }
 }
diff --git a/core/src/main/java/com/google/bitcoin/core/Transaction.java b/core/src/main/java/com/google/bitcoin/core/Transaction.java
index 58c57180..40e79626 100644
--- a/core/src/main/java/com/google/bitcoin/core/Transaction.java
+++ b/core/src/main/java/com/google/bitcoin/core/Transaction.java
@@ -941,6 +941,17 @@ public class Transaction extends ChildMessage implements Serializable {
         maybeParse();
         return Collections.unmodifiableList(outputs);
     }
+
+    /** @return the given transaction: same as getInputs().get(index). */
+    public TransactionInput getInput(int index) {
+        maybeParse();
+        return inputs.get(index);
+    }
+
+    public TransactionOutput getOutput(int index) {
+        maybeParse();
+        return outputs.get(index);
+    }
     
     public synchronized TransactionConfidence getConfidence() {
         if (confidence == null) {