diff --git a/utils/nio/src/main/java/org/onlab/nio/Message.java b/utils/nio/src/main/java/org/onlab/nio/Message.java
new file mode 100644
index 0000000..5ce6d44
--- /dev/null
+++ b/utils/nio/src/main/java/org/onlab/nio/Message.java
@@ -0,0 +1,15 @@
+package org.onlab.nio;
+
+/**
+ * Representation of a message transferred via {@link MessageStream}.
+ */
+public interface Message {
+
+    /**
+     * Gets the message length in bytes.
+     *
+     * @return number of bytes
+     */
+    int length();
+
+}