diff --git a/ChatApp/src/App.java b/ChatApp/src/App.java
deleted file mode 100644
index 0a839f9..0000000
--- a/ChatApp/src/App.java
+++ /dev/null
@@ -1,5 +0,0 @@
-public class App {
-    public static void main(String[] args) throws Exception {
-        System.out.println("Hello, World!");
-    }
-}
diff --git a/ChatApp/src/ChatApp.java b/ChatApp/src/ChatApp.java
new file mode 100644
index 0000000..872047b
--- /dev/null
+++ b/ChatApp/src/ChatApp.java
@@ -0,0 +1,15 @@
+import java.net.InetSocketAddress;
+
+import client.Client;
+import server.Server;
+
+public class ChatApp {
+    public static void main(String[] args) throws Exception {
+        Server server = new Server(6665);
+        Client client = new Client(new InetSocketAddress("localhost", 6665));
+
+        while (true) {
+
+        }
+    }
+}
diff --git a/ChatApp/src/client/Client.java b/ChatApp/src/client/Client.java
new file mode 100644
index 0000000..2b30fcb
--- /dev/null
+++ b/ChatApp/src/client/Client.java
@@ -0,0 +1,35 @@
+package client;
+
+import java.io.IOException;
+import java.net.DatagramSocket;
+import java.net.InetSocketAddress;
+import java.net.SocketException;
+
+import network.protocol.packets.LoginPacket;
+import network.protocol.packets.SendChatMessagePacket;
+
+public class Client {
+
+	private final ClientConnexion connexion;
+
+	public Client(InetSocketAddress serverAddress) throws SocketException {
+		this.connexion = new ClientConnexion(new DatagramSocket(), serverAddress);
+		login("Moi");
+	}
+
+	private void login(String pseudo) {
+		try {
+			this.connexion.sendPacket(new LoginPacket(pseudo));
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
+	}
+
+	public void SendChatMessage(String message) {
+		try {
+			this.connexion.sendPacket(new SendChatMessagePacket(message));
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
+	}
+}
diff --git a/ChatApp/src/client/ClientConnexion.java b/ChatApp/src/client/ClientConnexion.java
new file mode 100644
index 0000000..1d22351
--- /dev/null
+++ b/ChatApp/src/client/ClientConnexion.java
@@ -0,0 +1,94 @@
+package client;
+
+import java.io.IOException;
+import java.net.DatagramSocket;
+import java.net.InetSocketAddress;
+
+import network.PacketHandler;
+import network.SocketReader;
+import network.SocketWriter;
+import network.protocol.Packet;
+import network.protocol.PacketVisitor;
+import network.protocol.packets.ChatMessagePacket;
+import network.protocol.packets.CreateRoomPacket;
+import network.protocol.packets.JoinRoomPacket;
+import network.protocol.packets.LeaveRoomPacket;
+import network.protocol.packets.LoginPacket;
+import network.protocol.packets.RequestRoomListPacket;
+import network.protocol.packets.RoomListPacket;
+import network.protocol.packets.SendChatMessagePacket;
+import network.protocol.packets.ServerResponsePacket;
+
+public class ClientConnexion implements PacketVisitor, PacketHandler{
+
+	private final InetSocketAddress serverAddress;
+	private final SocketWriter writer;
+	private final SocketReader reader;
+
+	public ClientConnexion(DatagramSocket socket, InetSocketAddress serverAddress) {
+		this.serverAddress = serverAddress;
+		this.writer = new SocketWriter(socket);
+		this.reader = new SocketReader(socket, this);
+	}
+
+	public void close() {
+		this.reader.stop();
+	}
+
+	public void sendPacket(Packet packet) throws IOException {
+		this.writer.sendPacket(packet, serverAddress);
+	}
+
+	@Override
+	public void handlePacket(Packet packet, InetSocketAddress address) {
+		// we assume that the packet comes from the server
+		visit(packet);
+	}
+
+	@Override
+	public void visitPacket(ChatMessagePacket packet) {
+		throw new UnsupportedOperationException("Unimplemented method 'visitPacket'");
+	}
+
+	@Override
+	public void visitPacket(CreateRoomPacket packet) {
+		throw new UnsupportedOperationException("Unimplemented method 'visitPacket'");
+	}
+
+	@Override
+	public void visitPacket(JoinRoomPacket packet) {
+		throw new UnsupportedOperationException("Unimplemented method 'visitPacket'");
+	}
+
+	@Override
+	public void visitPacket(LeaveRoomPacket packet) {
+		throw new UnsupportedOperationException("Unimplemented method 'visitPacket'");
+	}
+
+	@Override
+	public void visitPacket(LoginPacket packet) {
+		throw new UnsupportedOperationException("Unimplemented method 'visitPacket'");
+	}
+
+	@Override
+	public void visitPacket(RequestRoomListPacket packet) {
+		throw new UnsupportedOperationException("Unimplemented method 'visitPacket'");
+	}
+
+	@Override
+	public void visitPacket(RoomListPacket packet) {
+		System.out.println("Handled room list !");
+		// throw new UnsupportedOperationException("Unimplemented method 'visitPacket'");
+	}
+
+	@Override
+	public void visitPacket(SendChatMessagePacket packet) {
+		throw new UnsupportedOperationException("Unimplemented method 'visitPacket'");
+	}
+
+	@Override
+	public void visitPacket(ServerResponsePacket packet) {
+		System.out.println(packet.getResponse());
+	}
+
+}
diff --git a/ChatApp/src/network/PacketHandler.java b/ChatApp/src/network/PacketHandler.java
new file mode 100644
index 0000000..23f935f
--- /dev/null
+++ b/ChatApp/src/network/PacketHandler.java
@@ -0,0 +1,9 @@
+package network;
+
+import java.net.InetSocketAddress;
+
+import network.protocol.Packet;
+
+public interface PacketHandler {
+	void handlePacket(Packet packet, InetSocketAddress address);
+}
diff --git a/ChatApp/src/network/SocketReader.java b/ChatApp/src/network/SocketReader.java
new file mode 100644
index 0000000..dba0724
--- /dev/null
+++ b/ChatApp/src/network/SocketReader.java
@@ -0,0 +1,48 @@
+package network;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.net.DatagramPacket;
+import java.net.DatagramSocket;
+import java.net.InetSocketAddress;
+
+import network.protocol.Packet;
+
+public class SocketReader {
+
+	private final DatagramSocket socket;
+	private final Thread readThread;
+	private final PacketHandler handler;
+
+	public SocketReader(DatagramSocket socket, PacketHandler handler) {
+		this.socket = socket;
+		this.handler = handler;
+		this.readThread = new Thread(this::readLoop);
+		this.readThread.start();
+	}
+
+	public void stop() {
+		this.readThread.interrupt();
+	}
+
+	private void readLoop() {
+		while (!Thread.interrupted()) {
+			try {
+				byte[] buffer = new byte[65535];
+				DatagramPacket dataPacket = new DatagramPacket(buffer, buffer.length);
+				socket.receive(dataPacket);
+				
+				InetSocketAddress address = new InetSocketAddress(dataPacket.getAddress(), dataPacket.getPort());
+				
+				ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream(dataPacket.getData()));
+				Packet packet = (Packet) ois.readObject();
+
+				this.handler.handlePacket(packet, address);
+			} catch (IOException | ClassNotFoundException e) {
+				e.printStackTrace();
+			}
+		}
+	}
+
+}
diff --git a/ChatApp/src/network/SocketWriter.java b/ChatApp/src/network/SocketWriter.java
new file mode 100644
index 0000000..54c4d41
--- /dev/null
+++ b/ChatApp/src/network/SocketWriter.java
@@ -0,0 +1,30 @@
+package network;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.ObjectOutputStream;
+import java.net.DatagramPacket;
+import java.net.DatagramSocket;
+import java.net.InetSocketAddress;
+
+import network.protocol.Packet;
+
+public class SocketWriter {
+
+	private final DatagramSocket socket;
+
+	public SocketWriter(DatagramSocket socket) {
+		this.socket = socket;
+	}
+
+	public void sendPacket(Packet packet, InetSocketAddress address) throws IOException {
+		ByteArrayOutputStream stream = new ByteArrayOutputStream();
+		ObjectOutputStream oos = new ObjectOutputStream(stream);
+		oos.writeObject(packet);
+		oos.flush();
+		byte[] data = stream.toByteArray();
+		DatagramPacket dataPacket = new DatagramPacket(data, data.length, address.getAddress(),
+				address.getPort());
+		this.socket.send(dataPacket);
+	}
+}
diff --git a/ChatApp/src/server/Server.java b/ChatApp/src/server/Server.java
new file mode 100644
index 0000000..c7acc6b
--- /dev/null
+++ b/ChatApp/src/server/Server.java
@@ -0,0 +1,52 @@
+package server;
+
+import java.net.DatagramSocket;
+import java.net.InetSocketAddress;
+import java.net.SocketException;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.Map;
+
+import network.PacketHandler;
+import network.SocketReader;
+import network.protocol.Packet;
+
+public class Server implements PacketHandler {
+
+	private final DatagramSocket serverSocket;
+	private final Map<InetSocketAddress, ServerConnexion> connexions;
+	private final SocketReader reader;
+	private final ArrayList<String> roomNames;
+
+	public Server(int port) throws SocketException {
+		this.serverSocket = new DatagramSocket(port);
+		this.connexions = new HashMap<>();
+		this.reader = new SocketReader(serverSocket, this);
+		this.roomNames = new ArrayList<>();
+	}
+
+	public ArrayList<String> getRoomNames() {
+		return roomNames;
+	}
+
+	public void close() {
+		this.reader.stop();
+	}
+
+	public boolean hasChatterName(String pseudo) {
+		for (var entry : this.connexions.entrySet()) {
+			if (pseudo.equals(entry.getValue().getChatterName()))
+				return true;
+		}
+		return false;
+	}
+
+	@Override
+	public void handlePacket(Packet packet, InetSocketAddress address) {
+		if (!connexions.containsKey(address)) {
+			this.connexions.put(address, new ServerConnexion(this, serverSocket, address));
+		}
+		this.connexions.get(address).visit(packet);
+	}
+
+}
diff --git a/ChatApp/src/server/ServerConnexion.java b/ChatApp/src/server/ServerConnexion.java
new file mode 100644
index 0000000..2cb0416
--- /dev/null
+++ b/ChatApp/src/server/ServerConnexion.java
@@ -0,0 +1,98 @@
+package server;
+
+import java.io.IOException;
+import java.net.DatagramSocket;
+import java.net.InetSocketAddress;
+
+import network.SocketWriter;
+import network.protocol.Packet;
+import network.protocol.PacketVisitor;
+import network.protocol.packets.ChatMessagePacket;
+import network.protocol.packets.CreateRoomPacket;
+import network.protocol.packets.JoinRoomPacket;
+import network.protocol.packets.LeaveRoomPacket;
+import network.protocol.packets.LoginPacket;
+import network.protocol.packets.RequestRoomListPacket;
+import network.protocol.packets.RoomListPacket;
+import network.protocol.packets.SendChatMessagePacket;
+import network.protocol.packets.ServerResponsePacket;
+import network.protocol.packets.ServerResponsePacket.Response;
+
+public class ServerConnexion implements PacketVisitor {
+
+	private final Server server;
+	private final InetSocketAddress clientAddress;
+	private final SocketWriter writer;
+	private String chatterName;
+
+	public ServerConnexion(Server server, DatagramSocket socket, InetSocketAddress clientAddress) {
+		this.clientAddress = clientAddress;
+		this.server = server;
+		this.writer = new SocketWriter(socket);
+	}
+
+	public String getChatterName() {
+		return this.chatterName;
+	}
+
+	public void sendPacket(Packet packet) {
+		try {
+			this.writer.sendPacket(packet, clientAddress);
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
+	}
+
+	@Override
+	public void visitPacket(ChatMessagePacket packet) {
+		throw new UnsupportedOperationException("Unimplemented method 'visitPacket'");
+	}
+
+	@Override
+	public void visitPacket(CreateRoomPacket packet) {
+		throw new UnsupportedOperationException("Unimplemented method 'visitPacket'");
+	}
+
+	@Override
+	public void visitPacket(JoinRoomPacket packet) {
+		throw new UnsupportedOperationException("Unimplemented method 'visitPacket'");
+	}
+
+	@Override
+	public void visitPacket(LeaveRoomPacket packet) {
+		throw new UnsupportedOperationException("Unimplemented method 'visitPacket'");
+	}
+
+	@Override
+	public void visitPacket(LoginPacket packet) {
+		if (server.hasChatterName(packet.getPseudo())) {
+			sendPacket(new ServerResponsePacket(Response.AuthError));
+			return;
+		}
+
+		this.chatterName = packet.getPseudo();
+		sendPacket(new RoomListPacket(server.getRoomNames()));
+		System.out.println("[Server] Chatter " + packet.getPseudo() + " connected !");
+	}
+
+	@Override
+	public void visitPacket(RequestRoomListPacket packet) {
+		throw new UnsupportedOperationException("Unimplemented method 'visitPacket'");
+	}
+
+	@Override
+	public void visitPacket(RoomListPacket packet) {
+		throw new UnsupportedOperationException("Unimplemented method 'visitPacket'");
+	}
+
+	@Override
+	public void visitPacket(SendChatMessagePacket packet) {
+		throw new UnsupportedOperationException("Unimplemented method 'visitPacket'");
+	}
+
+	@Override
+	public void visitPacket(ServerResponsePacket packet) {
+		throw new UnsupportedOperationException("Unimplemented method 'visitPacket'");
+	}
+
+}