diff --git a/Server/Server.cpp b/Server/Server.cpp
index 15bfec9..677b7e2 100644
--- a/Server/Server.cpp
+++ b/Server/Server.cpp
@@ -6,7 +6,7 @@
 /*   By: aortigos <aortigos@student.42malaga.com    +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2026/05/06 17:19:12 by iherman-          #+#    #+#             */
-/*   Updated: 2026/05/14 17:00:22 by aortigos         ###   ########.fr       */
+/*   Updated: 2026/05/14 20:35:49 by aortigos         ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -113,6 +113,7 @@ Server::Server(int port, const std::string& password) :
 
 	// Add all new commands to commands_ here
 	commands_["PASS"] = &Server::pass_cmd;
+	commands_["NICK"] = &Server::nick_cmd;
 
 	std::cout << "Server port: " << port_
 		<< "\nServer Password: " << password_
diff --git a/Server/Server.hpp b/Server/Server.hpp
index b87aea8..6fd8ed1 100644
--- a/Server/Server.hpp
+++ b/Server/Server.hpp
@@ -6,7 +6,7 @@
 /*   By: aortigos <aortigos@student.42malaga.com    +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2026/05/06 17:18:11 by iherman-          #+#    #+#             */
-/*   Updated: 2026/05/14 16:58:31 by aortigos         ###   ########.fr       */
+/*   Updated: 2026/05/14 20:35:22 by aortigos         ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -24,6 +24,8 @@
 
 # include "../User/User.hpp"
 
+
+# define SERVER_NAME irc.server
 # define PORT_DEFAULT 9898
 
 class Server
@@ -53,6 +55,7 @@ class Server
 
 		// Commands
 		void	pass_cmd(User &client, std::istringstream &ss);
+		void	nick_cmd(User &client, std::istringstream &ss);
 
 
 	public:
diff --git a/cmds/nick.cpp b/cmds/nick.cpp
new file mode 100644
index 0000000..f80a896
--- /dev/null
+++ b/cmds/nick.cpp
@@ -0,0 +1,28 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   nick.cpp                                           :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: aortigos <aortigos@student.42malaga.com    +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2026/05/10 22:06:22 by aortigos          #+#    #+#             */
+/*   Updated: 2026/05/14 20:38:44 by aortigos         ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "../Server/Server.hpp"
+
+void	Server::nick_cmd(User &client, std::istringstream &ss)
+{
+	std::string		args;
+
+	ss >> args;
+	if (args.empty())
+		return (client.send(":" SERVER_NAME " 431 * :Not nickname given\r\n"));
+	// Invalid characters in nick
+		// 432 * badnick : Erroneous nickname
+	// If nick exists
+		// 4233 * takenick :Nickname is already in use
+	if (client.getUsername())
+		return (); // Broadcast in channels :oldnick!user@host NICK newnick
+}
\ No newline at end of file
diff --git a/cmds/pass.cpp b/cmds/pass.cpp
index 7b409c2..d842bd5 100644
--- a/cmds/pass.cpp
+++ b/cmds/pass.cpp
@@ -6,7 +6,7 @@
 /*   By: aortigos <aortigos@student.42malaga.com    +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2026/05/10 22:06:22 by aortigos          #+#    #+#             */
-/*   Updated: 2026/05/14 17:23:56 by aortigos         ###   ########.fr       */
+/*   Updated: 2026/05/14 20:21:31 by aortigos         ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -17,17 +17,13 @@ void	Server::pass_cmd(User &client, std::istringstream &ss)
 	std::string		args;
 
 	ss >> args;
+	if (args.empty())
+		return (client.send(":" SERVER_NAME " 461 * PASS :Not enough parameters\r\n"));
 	if (client.isAuthenticated())
-	{
-		// Still need to find what server should reply to different errors
-		client.send("You are already logged in\r\n");
-		return ;
-	}
+		return (client.send(":" SERVER_NAME " 462 " + client.getNick() + " :Unauthorized command (already registered)\r\n"));
 	if (this->password_ == args)
 		client.setAuthenticated(true);
 	else {
-		// Still need to find what server should reply to different errors
-		client.send("Invalid password\r\n");
-		send(client.getFd(), res.c_str(), res.size(), 0);
+		client.send(":" SERVER_NAME " 464 * :Password incorrect\r\n");
 	}
 }
\ No newline at end of file