diff --git a/SimpleTCP/Message.cs b/SimpleTCP/Message.cs
index d9d9a6a..130a84d 100644
--- a/SimpleTCP/Message.cs
+++ b/SimpleTCP/Message.cs
@@ -7,7 +7,17 @@
 
 namespace SimpleTCP
 {
-    public class Message
+    public interface IMessage
+    {
+        byte[] Data { get; }
+        string MessageString { get; }
+        void Reply(byte[] data);
+        void Reply(string data);
+        void ReplyLine(string data);
+        TcpClient TcpClient { get; }
+    }
+
+    public class Message : IMessage
     {
         private TcpClient _tcpClient;
         private System.Text.Encoding _encoder = null;
diff --git a/SimpleTCP/SimpleTcpClient.cs b/SimpleTCP/SimpleTcpClient.cs
index 5c66a93..f432476 100644
--- a/SimpleTCP/SimpleTcpClient.cs
+++ b/SimpleTCP/SimpleTcpClient.cs
@@ -9,7 +9,20 @@
 
 namespace SimpleTCP
 {
-	public class SimpleTcpClient : IDisposable
+    public interface ISimpleTcpClient : IDisposable
+    {
+        byte Delimiter { get; set; }
+        Encoding StringEncoder { get; set; }
+        bool AutoTrimStrings { get; set; }
+        SimpleTcpClient Connect(string hostNameOrIpAddress, int port);
+        SimpleTcpClient Disconnect();
+        TcpClient TcpClient { get; }
+        void Write(byte[] data);
+        void Write(string data);
+        Message WriteLineAndGetReply(string data, TimeSpan timeout);
+    }
+
+	public class SimpleTcpClient : ISimpleTcpClient
 	{
 		public SimpleTcpClient()
 		{
diff --git a/SimpleTCP/SimpleTcpServer.cs b/SimpleTCP/SimpleTcpServer.cs
index 15d1509..b13518d 100644
--- a/SimpleTCP/SimpleTcpServer.cs
+++ b/SimpleTCP/SimpleTcpServer.cs
@@ -11,7 +11,28 @@
 
 namespace SimpleTCP
 {
-    public class SimpleTcpServer
+    public interface ISimpleTcpServer
+    {
+        byte Delimiter { get; set; }
+        Encoding StringEncoder { get; set; }
+        bool AutoTrimStrings { get; set; }
+        event EventHandler<TcpClient> ClientConnected;
+        event EventHandler<TcpClient> ClientDisconnected;
+        event EventHandler<Message> DelimiterDataReceived;
+        event EventHandler<Message> DataReceived;
+        IEnumerable<IPAddress> GetIPAddresses();
+        List<IPAddress> GetListeningIPs();
+        void Broadcast(byte[] data);
+        void Broadcast(string data);
+        void BroadcastLine(string data);
+        SimpleTcpServer Start(int port, bool ignoreNicsWithOccupiedPorts = true);
+        SimpleTcpServer Start(int port, AddressFamily addressFamilyFilter);
+        SimpleTcpServer Start(IPAddress ipAddress, int port);
+        void Stop();
+        int ConnectedClientsCount { get; }
+    }
+
+    public class SimpleTcpServer : ISimpleTcpServer
     {
         public SimpleTcpServer()
         {