diff --git a/app/connection.php b/app/connection.php
new file mode 100644
index 0000000..80d3fc8
--- /dev/null
+++ b/app/connection.php
@@ -0,0 +1,29 @@
+<?php
+namespace Config;
+use PDO;
+use PDOStatement;
+
+class Connection extends PDO{
+    private PDOStatement $stmt;
+
+    public function __construct(string $dsn, string $username, string $password)
+    {
+        parent::__construct($dsn, $username, $password);
+        $this->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
+    }
+
+    public function executeQuery(string $query, array $parameters = []): bool
+    {
+        $this->stmt = parent::prepare($query);
+        foreach ($parameters as $name => $value) {
+            $this->stmt->bindValue($name, $value[0], $value[1]);
+        }
+
+        return $this->stmt->execute();
+    }
+
+    public function getResults(): array
+    {
+        return $this->stmt->fetchAll();
+    }
+}
diff --git a/app/database_con.php b/app/database_con.php
new file mode 100644
index 0000000..fe11c14
--- /dev/null
+++ b/app/database_con.php
@@ -0,0 +1,28 @@
+<?php
+namespace Config;
+use PDOException;
+require_once __DIR__ ."/connection.php";
+
+class DatabaseCon{
+    private string $dsn;
+    private string $login;
+    private string $password;
+
+    function __construct(){
+        if (getenv("SMDB_HOST") == null || getenv("SMDB_DATABASE") == null || getenv("SMDB_USER") == null || getenv("SMDB_PASSWORD") == null){
+            throw new PDOException("ENV variables not found");
+        }
+        $this->dsn = "mysql:host=".getenv("SMDB_HOST").";dbname=".getenv("SMDB_DATABASE").";charset=UTF8";
+        $this->login = getenv("SMDB_USER");
+        $this->password = getenv("SMDB_PASSWORD");
+    }
+
+    function connect(): int|Connection {
+        try {
+            $connection = new Connection($this->dsn,$this->login,$this->password);
+        } catch (PDOException $e){
+            throw new PDOException($e->getMessage(), $e->getCode(), $e);
+        }
+        return $connection;
+    }
+}
diff --git a/app/gateway/user_gateway.php b/app/gateway/user_gateway.php
new file mode 100644
index 0000000..f11703f
--- /dev/null
+++ b/app/gateway/user_gateway.php
@@ -0,0 +1,84 @@
+<?php
+namespace Gateway;
+use Config\DatabaseCon;
+use Config\Connection;
+use PDOException;
+use PDO;
+use Config\Token;
+
+class UserGateway {
+    private Connection $con;
+    private Token $token;
+
+    public function __construct() {
+        $this->token = new Token;
+    	try {
+            $this->con = (new DatabaseCon)->connect();
+        } catch(PDOException $e) {
+            throw new PDOException($e->getMessage(), $e->getCode(), $e);
+        }
+    }
+
+    public function createUser(string $mail, string $hash, string $username) {
+        $query = "INSERT INTO user VALUES(UUID(), :mail, :hash, :username, CURDATE());";
+        $this->con->executeQuery($query, array(
+            ':mail' => array($mail, PDO::PARAM_STR),
+            ':hash' => array($hash, PDO::PARAM_STR),
+            ':username' => array($username, PDO::PARAM_STR)
+        ));
+
+        $query = "SELECT id FROM user WHERE email=:mail;";
+        $this->con->executeQuery($query, array(
+            ':mail' => array($mail, PDO::PARAM_STR)
+        ));
+        $results = $this->con->getResults();
+        
+        return $this->token->getNewJsonToken($results[0]['id']);        
+    }
+
+    // Delete User: (1:OK, 2:Unauthorize, 3:No User)
+    public function deleteUser(string $uuid) : int {
+        $query = "DELETE FROM user WHERE id=:uuid;";
+        $this->con->executeQuery($query, array(
+            ':uuid' => array($uuid, PDO::PARAM_STR)
+        ));
+
+        return 0;
+    }
+
+    // Login User (get token)
+    public function login(string $mail, string $hash) {
+        $query = "SELECT hash, id FROM user WHERE email=:mail;";
+        $this->con->executeQuery($query, array(
+            ':mail' => array($mail, PDO::PARAM_STR)
+        ));
+        $results = $this->con->getResults();
+        
+        if(empty($results)) {
+            // Not Found
+            return 404; 
+        }
+        if($hash !== (string) $results[0]['hash']) {
+            // Unauthorized
+            return 401;
+        }
+                
+        return json_encode($this->token->getNewJsonToken($results[0]['id'])); 
+    }
+
+    public function updateMail(string $uuid, string $new_mail) {
+        $query = "UPDATE user SET email=:new_mail WHERE id=:uuid;";
+        $this->con->executeQuery($query, array(
+            ':new_mail' => array($new_mail, PDO::PARAM_STR),
+            ':uuid' => array($uuid, PDO::PARAM_STR)
+        ));
+    }
+
+    public function updateUsername(string $uuid, string $new_username) {
+        $query = "UPDATE user SET username=:new_username WHERE id=:uuid;";
+        $this->con->executeQuery($query, array(
+            ':new_username' => array($new_username, PDO::PARAM_STR),
+            ':uuid' => array($uuid, PDO::PARAM_STR)
+        ));
+    }
+}
\ No newline at end of file
diff --git a/app/routes.php b/app/routes.php
index cc84b83..5495bce 100644
--- a/app/routes.php
+++ b/app/routes.php
@@ -1,10 +1,14 @@
 <?php
-
 declare(strict_types=1);
+require "gateway/user_gateway.php";
+require "database_con.php";
+require "token.php";
 
 use Psr\Http\Message\ResponseInterface as Response;
 use Psr\Http\Message\ServerRequestInterface as Request;
 use Slim\App;
+use gateway\UserGateway;
+use Config\Token;
 
 return function (App $app) {
 
@@ -16,43 +20,66 @@ return function (App $app) {
     #### ACCOUNT ####
     // Create User 
     $app->post('/user', function (Request $req, Response $res) {
-        $res->getBody()->write('/user');
+        $req_body = $req->getParsedBody();
+        $res->getBody()->write(json_encode((new UserGateway)->createUser($req_body['mail'], $req_body['password'], $req_body['user'])));
         return $res;
     });
 
     // Delete User 
     $app->delete('/user', function (Request $req, Response $res) {
         $token = $req->getHeader('Authorization')[0];
-        
-        $res->getBody()->write('/user/' . $token);
-        return $res;
+        $uuid = (new Token)->getUuidFromToken($token);
+        $code = (new UserGateway)->deleteUser($uuid);
+
+        switch($code) {
+            case  0:
+                return $res->withStatus(200);
+            case -1:
+                return $res->withStatus(401);
+            case -2:
+                return $res->withStatus(404);
+        }
+        return $res->withStatus(500);
     });
 
     // Get Token
-    $app->get('/user/{uuid}/{hash}/token', function (Request $req, Response $res, $args) {
-        $uuid = $args['uuid'];
+    $app->get('/user/login/{mail}/{hash}', function (Request $req, Response $res, $args) {
+        $mail = $args['mail'];
         $hash = $args['hash'];
         
-        $res->getBody()->write('/user/' . $uuid . '/' . $hash);
+        $value = (new UserGateway)->login($mail, $hash);
+        // If error statusCode else token
+        if($value instanceOf int) {
+            return $res->withStatus($value);
+        }
+        $res->getBody()->write($value);
         return $res;
     });
 
     // Update Mail
     $app->put('/user/mail', function(Request $req, Response $res) {
         $token = $req->getHeader('Authorization')[0];
-        $mail = $req->getParsedBody()['mail'];
-
-        $res->getBody()->write('/user/mail mail:'.$mail.' Auth:'.$token);
-        return $res; 
+        $new_mail = $req->getParsedBody()['mail'];
+        if(!(new Token)->verifyToken($token)) {
+            return $res->withStatus(401);
+        }
+        
+        $uuid = (new Token)->getUuidFromToken($token);
+        (new UserGateway)->updateMail($uuid, $new_mail);
+        return $res->withStatus(200); 
     });
 
     // Update Username
     $app->put('/user/username', function(Request $req, Response $res) {
         $token = $req->getHeader('Authorization')[0];
-        $username = $req->getParsedBody()['username'];
-
-        $res->getBody()->write('/user/username username:'.$username.' Auth:'.$token);
-        return $res; 
+        $new_username = $req->getParsedBody()['username'];
+        if(!(new Token)->verifyToken($token)) {
+            return $res->withStatus(401);
+        }
+        
+        $uuid = (new Token)->getUuidFromToken($token);
+        (new UserGateway)->updateUsername($uuid, $new_username);
+        return $res->withStatus(200);
     });
 
     #### FILES ####
@@ -89,5 +116,4 @@ return function (App $app) {
         $res->getBody()->write('/user/files'.' Auth:'.$token);
         return $res;
     });
-
 };
\ No newline at end of file
diff --git a/app/token.php b/app/token.php
new file mode 100644
index 0000000..734d49c
--- /dev/null
+++ b/app/token.php
@@ -0,0 +1,46 @@
+<?php
+namespace Config;
+
+use Exception;
+use Firebase\JWT\JWT;
+use Firebase\JWT\Key;
+
+class Token {
+    private string $key = 'passwd';
+    // Need to be in a config file
+    private string $path_to_key="../sym_keyfile.key";
+    
+    function __construct()
+    {
+    	#$file = fopen($this->path_to_key, 'r');
+        #$this->key = fread($file, filesize($this->path_to_key));
+        #fclose($file);
+    }
+
+    // Return json containing JWT with uuid and exp
+    function getNewJsonToken(string $uuid) :array {
+        $payload = [
+            'uuid' => $uuid,
+            'exp' => strtotime("+2month", time())
+        ];
+        
+        return ["token" => JWT::encode($payload, $this->key, 'HS256')];
+    }
+
+    // Verify the JWT authenticity
+    function verifyToken(string $jwt) :bool {
+        try {
+            JWT::decode($jwt, new Key($this->key, 'HS256'));
+        } catch (Exception $e) {
+            return false;
+        }
+        return true;
+    }
+
+    // Get uuid from JWT
+    // Missing error handling on bad JWT
+    function getUuidFromToken(string $jwt) :string {
+        $decoded = (array) JWT::decode($jwt, new Key($this->key, 'HS256'));
+        return $decoded['uuid'];
+    }
+}
\ No newline at end of file
diff --git a/composer.json b/composer.json
index 6b8de2a..8613b6d 100644
--- a/composer.json
+++ b/composer.json
@@ -24,6 +24,7 @@
     "require": {
         "php": "^7.4 || ^8.0",
         "ext-json": "*",
+        "firebase/php-jwt": "^6.9",
         "monolog/monolog": "^2.8",
         "php-di/php-di": "^6.4",
         "slim/psr7": "^1.5",
diff --git a/composer.lock b/composer.lock
index 69ca691..43593ec 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "62d60de4b802ec31b840b9197e947981",
+    "content-hash": "3fbd2a92a15c13f23e25e12b030b51e6",
     "packages": [
         {
             "name": "fig/http-message-util",
@@ -62,6 +62,69 @@
             },
             "time": "2020-11-24T22:02:12+00:00"
         },
+        {
+            "name": "firebase/php-jwt",
+            "version": "v6.9.0",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/firebase/php-jwt.git",
+                "reference": "f03270e63eaccf3019ef0f32849c497385774e11"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/firebase/php-jwt/zipball/f03270e63eaccf3019ef0f32849c497385774e11",
+                "reference": "f03270e63eaccf3019ef0f32849c497385774e11",
+                "shasum": ""
+            },
+            "require": {
+                "php": "^7.4||^8.0"
+            },
+            "require-dev": {
+                "guzzlehttp/guzzle": "^6.5||^7.4",
+                "phpspec/prophecy-phpunit": "^2.0",
+                "phpunit/phpunit": "^9.5",
+                "psr/cache": "^1.0||^2.0",
+                "psr/http-client": "^1.0",
+                "psr/http-factory": "^1.0"
+            },
+            "suggest": {
+                "ext-sodium": "Support EdDSA (Ed25519) signatures",
+                "paragonie/sodium_compat": "Support EdDSA (Ed25519) signatures when libsodium is not present"
+            },
+            "type": "library",
+            "autoload": {
+                "psr-4": {
+                    "Firebase\\JWT\\": "src"
+                }
+            },
+            "notification-url": "https://packagist.org/downloads/",
+            "license": [
+                "BSD-3-Clause"
+            ],
+            "authors": [
+                {
+                    "name": "Neuman Vong",
+                    "email": "neuman+pear@twilio.com",
+                    "role": "Developer"
+                },
+                {
+                    "name": "Anant Narayanan",
+                    "email": "anant@php.net",
+                    "role": "Developer"
+                }
+            ],
+            "description": "A simple library to encode and decode JSON Web Tokens (JWT) in PHP. Should conform to the current spec.",
+            "homepage": "https://github.com/firebase/php-jwt",
+            "keywords": [
+                "jwt",
+                "php"
+            ],
+            "support": {
+                "issues": "https://github.com/firebase/php-jwt/issues",
+                "source": "https://github.com/firebase/php-jwt/tree/v6.9.0"
+            },
+            "time": "2023-10-05T00:24:42+00:00"
+        },
         {
             "name": "laravel/serializable-closure",
             "version": "v1.3.2",