diff --git a/public/assets/js/app.js b/public/assets/js/app.js
index 594f52a..c2b3b7a 100644
--- a/public/assets/js/app.js
+++ b/public/assets/js/app.js
@@ -1,5 +1,3 @@
-// main.js
-
 document.addEventListener('DOMContentLoaded', function() {
     const addBillForm = document.getElementById('addBillForm');
     if (addBillForm) {
@@ -8,37 +6,12 @@ document.addEventListener('DOMContentLoaded', function() {
             const formData = new FormData(this);
             axios.post('/api/add-bill', formData)
                 .then(function(response) {
-                    // Handle success, e.g., close modal, refresh bill list
                     console.log('Bill added successfully');
-                    loadBills(); // Reload the bills list
+                    loadBills();
                 })
                 .catch(function(error) {
-                    // Handle error, e.g., display error message
                     console.error('Error adding bill:', error);
                 });
-            
-            document.querySelectorAll('.edit-bill-btn').forEach(button => {
-                button.addEventListener('click', function() {
-                    const billId = this.getAttribute('data-bill-id');
-                    // Fetch bill details and populate the form in the modal
-                    // Then, handle the form submission similar to the add bill form
-                });
-            });
-            document.querySelectorAll('.delete-bill-btn').forEach(button => {
-                button.addEventListener('click', function() {
-                    const billId = this.getAttribute('data-bill-id');
-                    axios.post('/api/delete-bill', { id: billId })
-                        .then(function(response) {
-                            // Handle success
-                            console.log('Bill deleted successfully');
-                            loadBills(); // Reload the bills list
-                        })
-                        .catch(function(error) {
-                            // Handle error
-                            console.error('Error deleting bill:', error);
-                        });
-                });
-            });
         });
     }
 
@@ -46,17 +19,31 @@ document.addEventListener('DOMContentLoaded', function() {
     if (document.getElementById('billsTable')) {
         loadBills();
     }
-});
 
+    // Event delegation for dynamically added "Mark as Paid" buttons
+    document.addEventListener('click', function(e) {
+        if (e.target && e.target.matches('.mark-bill-paid-btn')) {
+            const billId = e.target.getAttribute('data-bill-id');
+            axios.post('/api/mark-bill-paid', { id: billId })
+                .then(function(response) {
+                    console.log('Bill marked as paid successfully');
+                    loadBills();
+                })
+                .catch(function(error) {
+                    console.error('Error marking bill as paid:', error);
+                });
+        }
+    });
+});
 
 function loadBills() {
     const billsTableBody = document.querySelector('#billsTable tbody');
-    billsTableBody.innerHTML = '<tr><td colspan="4" class="text-center">Loading bills...</td></tr>'; // Loading indicator
+    billsTableBody.innerHTML = '<tr><td colspan="4" class="text-center">Loading bills...</td></tr>';
 
     axios.get('/api/bills')
         .then(function(response) {
             const bills = response.data;
-            billsTableBody.innerHTML = ''; // Clear loading indicator
+            billsTableBody.innerHTML = '';
 
             bills.forEach(function(bill) {
                 const row = `
@@ -65,7 +52,9 @@ function loadBills() {
                         <td>$${parseFloat(bill.amount).toFixed(2)}</td>
                         <td>${bill.due_date}</td>
                         <td>
-                            <!-- Add action buttons here -->
+                        ${bill.is_paid ? '' : '<button type="button" class="btn btn-success btn-sm mark-bill-paid-btn" data-bill-id="' + bill.id + '">Mark as Paid</button>'}
+                        <button type="button" class="btn btn-primary btn-sm edit-bill-btn" data-bill-id="${bill.id}">Edit</button>
+                        <button type="button" class="btn btn-danger btn-sm delete-bill-btn" data-bill-id="${bill.id}">Delete</button>
                         </td>
                     </tr>
                 `;
@@ -74,6 +63,6 @@ function loadBills() {
         })
         .catch(function(error) {
             console.error('Error loading bills:', error);
-            billsTableBody.innerHTML = '<tr><td colspan="4" class="text-center">Error loading bills.</td></tr>'; // Error message
+            billsTableBody.innerHTML = '<tr><td colspan="4" class="text-center">Error loading bills.</td></tr>';
         });
 }
diff --git a/public/index.php b/public/index.php
index 91a135c..9cac678 100644
--- a/public/index.php
+++ b/public/index.php
@@ -1,181 +1,41 @@
 <?php
 
-use Hpz937\BillReminder\Bill\Bill;
-use Hpz937\BillReminder\Database\SQLiteAdapter;
+use Hpz937\BillReminder\Controller\HomeController;
+use Hpz937\BillReminder\Controller\AuthController;
+use Hpz937\BillReminder\Controller\DashboardController;
+use Hpz937\BillReminder\Controller\ApiController;
+use Hpz937\BillReminder\Routing\Router;
 
-require_once __DIR__ . '/../vendor/autoload.php';
+define('PROJECT_ROOT', __DIR__ . '/..');
+
+require_once PROJECT_ROOT . '/vendor/autoload.php';
 
 session_start();
 
-$request = $_SERVER['REQUEST_URI'];
+$router = new Router();
 
-// Initialize database connection
-// $dbConfig = require __DIR__ . '/../config/database.php'; // Assuming you have a config file
-$db = new \Hpz937\BillReminder\Database\SQLiteAdapter(); // Or whichever adapter you're using
+// Home Routes
+$router->register('GET', '/', [HomeController::class, 'index']);
 
+// Auth Routes
+$router->register('GET', '/login', [AuthController::class, 'showLoginForm']);
+$router->register('POST', '/login', [AuthController::class, 'login']);
+$router->register('GET', '/register', [AuthController::class, 'showRegistrationForm']);
+$router->register('POST', '/register', [AuthController::class, 'register']);
 
-switch ($request) {
-    case '/':
-        require __DIR__ . '/../views/home.php';
-        break;
-    case '/login':
-        if ($_SERVER['REQUEST_METHOD'] === 'POST') {
-            $username = $_POST['username'] ?? '';
-            $password = $_POST['password'] ?? '';
-    
-            if (empty($username) || empty($password)) {
-                $error = 'Username and password are required.';
-                require __DIR__ . '/../views/auth/login.php';
-                break;
-            }
-    
-            $user = new \Hpz937\BillReminder\User\User($db);
-            if ($user->login($username, $password)) {
-                header('Location: /dashboard');
-                exit;
-            } else {
-                $error = 'Login failed. Please check your credentials.';
-                require __DIR__ . '/../views/auth/login.php';
-            }
-        } else {
-            require __DIR__ . '/../views/auth/login.php';
-        }
-        break;
-        
-    case '/register':
-        if ($_SERVER['REQUEST_METHOD'] === 'POST') {
-            // Extract form data
-            $username = $_POST['username'] ?? '';
-            $password = $_POST['password'] ?? '';
-            $email = $_POST['email'] ?? '';
-    
-            // Perform validation (basic example)
-            if (empty($username) || empty($password) || empty($email)) {
-                // Handle validation error
-                $error = 'All fields are required.';
-                require __DIR__ . '/../views/auth/register.php';
-                break;
-            }
-    
-            // Instantiate User class and call register method
-            $user = new \Hpz937\BillReminder\User\User($db); // Assume $db is your DatabaseInterface instance
-            if ($user->register($username, $password, $email)) {
-                // Redirect to login on success
-                header('Location: /');
-                exit;
-            } else {
-                // Handle registration error
-                $error = 'Registration failed. Please try again.';
-                require __DIR__ . '/../views/auth/register.php';
-            }
-        } else {
-            require __DIR__ . '/../views/auth/register.php';
-        }
-        break;
-        
-    case '/dashboard':
-        if (!isset($_SESSION['user_id'])) {
-            header('Location: /login');
-            exit;
-        }
-        require __DIR__ . '/../views/dashboard.php';
-        break;
-    
-    case '/settings':
-        if (!isset($_SESSION['user_id'])) {
-            header('Location: /login');
-            exit;
-        }
-        require __DIR__ . '/../views/settings.php';
-        break;
+// Dashboard Routes
+$router->register('GET', '/dashboard', [DashboardController::class, 'viewDashboard']);
+$router->register('GET', '/settings', [DashboardController::class, 'viewSettings']);
 
-    case '/api/bills':
-        if (!isset($_SESSION['user_id'])) {
-            // Return an error response if the user is not logged in
-            echo json_encode(['error' => 'Unauthorized']);
-            http_response_code(401);
-            exit;
-        }
+// API Routes
+$router->register('GET', '/api/bills', [ApiController::class, 'getBills']);
+$router->register('POST', '/api/mark-bill-paid', [ApiController::class, 'markBillPaid']);
+$router->register('POST', '/api/add-bill', [ApiController::class, 'addBill']);
+$router->register('POST', '/api/edit-bill', [ApiController::class, 'editBill']);
+$router->register('POST', '/api/delete-bill', [ApiController::class, 'deleteBill']);
 
-        // Initialize your database and Bill class instance
-        $db = new SQLiteAdapter();
-        $billManager = new Bill($db);
+// Resolve the current request
+$requestMethod = $_SERVER['REQUEST_METHOD'];
+$requestUri = parse_url($_SERVER['REQUEST_URI'], PHP_URL_PATH);
 
-        $userId = $_SESSION['user_id'];
-        $bills = $billManager->getBillsByUserId($userId); // Assuming $billManager is your Bill class instance
-
-        // Return the bills as JSON
-        header('Content-Type: application/json');
-        echo json_encode($bills);
-        break;
-
-    case '/api/add-bill':
-        if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_SESSION['user_id'])) {
-            // Extract bill details from POST data
-            $userId = $_SESSION['user_id']; // Assuming you store user ID in session upon login
-            $description = $_POST['description'] ?? '';
-            $amount = $_POST['amount'] ?? '';
-            $dueDate = $_POST['due_date'] ?? '';
-    
-            // Validate the inputs...
-    
-            // Insert the bill into the database
-            $result = $billManager->addBill($userId, $dueDate, $amount, $description);
-    
-            if ($result) {
-                echo json_encode(['success' => 'Bill added successfully']);
-            } else {
-                http_response_code(500);
-                echo json_encode(['error' => 'Failed to add bill']);
-            }
-            exit;
-        }
-        break;
-
-    case '/api/edit-bill':
-        if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_SESSION['user_id'])) {
-            // Extract bill details and ID from POST data
-            $billId = $_POST['id'] ?? '';
-            $description = $_POST['description'] ?? '';
-            $amount = $_POST['amount'] ?? '';
-            $dueDate = $_POST['due_date'] ?? '';
-    
-            // Validate the inputs and ensure the bill belongs to the logged-in user...
-    
-            // Update the bill in the database
-            $result = $billManager->editBill($billId, $dueDate, $amount, $description);
-    
-            if ($result) {
-                echo json_encode(['success' => 'Bill updated successfully']);
-            } else {
-                http_response_code(500);
-                echo json_encode(['error' => 'Failed to update bill']);
-            }
-            exit;
-        }
-        break;
-    case '/api/delete-bill':
-        if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_SESSION['user_id'])) {
-            // Extract bill ID from POST data
-            $billId = $_POST['id'] ?? '';
-    
-            // Validate the ID and ensure the bill belongs to the logged-in user...
-    
-            // Delete the bill from the database
-            $result = $billManager->deleteBill($billId);
-    
-            if ($result) {
-                echo json_encode(['success' => 'Bill deleted successfully']);
-            } else {
-                http_response_code(500);
-                echo json_encode(['error' => 'Failed to delete bill']);
-            }
-            exit;
-        }
-        break;
-        
-    default:
-        http_response_code(404);
-        echo 'Page not found';
-        break;
-}
+$router->resolve($requestMethod, $requestUri);
diff --git a/src/Bill/Bill.php b/src/Bill/Bill.php
index 6ce8842..6d59b24 100644
--- a/src/Bill/Bill.php
+++ b/src/Bill/Bill.php
@@ -61,7 +61,8 @@ class Bill
             $this->db->query($sql, $params);
             return true;
         } catch (Exception $e) {
-            // Handle or log the error appropriately
+            //log the error
+            var_dump($e->getMessage());
             return false;
         }
     }
diff --git a/src/Controller/ApiController.php b/src/Controller/ApiController.php
new file mode 100644
index 0000000..9161226
--- /dev/null
+++ b/src/Controller/ApiController.php
@@ -0,0 +1,77 @@
+<?php
+
+namespace Hpz937\BillReminder\Controller;
+
+use Hpz937\BillReminder\Bill\Bill;
+use Hpz937\BillReminder\Database\SQLiteAdapter;
+
+class ApiController {
+    protected $db;
+
+    public function __construct() {
+        $this->db = new SQLiteAdapter();
+    }
+
+    public function getBills() {
+        if (!isset($_SESSION['user_id'])) {
+            echo json_encode(['error' => 'Unauthorized']);
+            http_response_code(401);
+            exit;
+        }
+
+        $billManager = new Bill($this->db);
+        $userId = $_SESSION['user_id'];
+        $bills = $billManager->getBillsByUserId($userId);
+
+        header('Content-Type: application/json');
+        echo json_encode($bills);
+    }
+
+    public function addBill() {
+        if (!isset($_SESSION['user_id'])) {
+            echo json_encode(['error' => 'Unauthorized or Invalid Request']);
+            http_response_code(401);
+            return;
+        }
+
+        $userId = $_SESSION['user_id'];
+        $description = $_POST['description'] ?? '';
+        $amount = $_POST['amount'] ?? '';
+        $dueDate = $_POST['due_date'] ?? '';
+
+        // Perform necessary validation on inputs
+
+        $billManager = new Bill($this->db);
+        $result = $billManager->addBill($userId, $description, $amount, $dueDate);
+
+        if ($result) {
+            echo json_encode(['success' => 'Bill added successfully']);
+        } else {
+            http_response_code(500);
+            echo json_encode(['error' => 'Failed to add bill']);
+        }
+    }
+
+    public function markBillPaid() {
+        if (!isset($_SESSION['user_id'])) {
+            echo json_encode(['error' => 'Unauthorized or Invalid Request']);
+            http_response_code(401);
+            return;
+        }
+
+        $json = json_decode(file_get_contents("php://input"), true);
+        $billId = $json['id'] ?? '';
+
+        // Perform necessary validation on inputs
+
+        $billManager = new Bill($this->db);
+        $result = $billManager->markAsPaid($billId);
+
+        if ($result) {
+            echo json_encode(['success' => 'Bill marked as paid']);
+        } else {
+            http_response_code(500);
+            echo json_encode(['error' => 'Failed to mark bill as paid']);
+        }
+    }
+}
diff --git a/src/Controller/AuthController.php b/src/Controller/AuthController.php
new file mode 100644
index 0000000..ca97d25
--- /dev/null
+++ b/src/Controller/AuthController.php
@@ -0,0 +1,62 @@
+<?php
+namespace Hpz937\BillReminder\Controller;
+
+use Hpz937\BillReminder\Database\SQLiteAdapter;
+use Hpz937\BillReminder\User\User;
+
+class AuthController {
+    protected $db;
+
+    public function __construct() {
+        $this->db = new SQLiteAdapter();
+    }
+
+    public function showLoginForm() {
+        require PROJECT_ROOT . '/views/auth/login.php';
+    }
+
+    public function login() {
+        $username = $_POST['username'] ?? '';
+        $password = $_POST['password'] ?? '';
+
+        if (empty($username) || empty($password)) {
+            $error = 'Username and password are required.';
+            require PROJECT_ROOT . '/views/auth/login.php';
+            return;
+        }
+
+        $user = new User($this->db);
+        if ($user->login($username, $password)) {
+            header('Location: /dashboard');
+            exit;
+        } else {
+            $error = 'Login failed. Please check your credentials.';
+            require PROJECT_ROOT . '/views/auth/login.php';
+        }
+    }
+
+    public function showRegistrationForm() {
+        require PROJECT_ROOT . '/views/auth/register.php';
+    }
+
+    public function register() {
+        $username = $_POST['username'] ?? '';
+        $password = $_POST['password'] ?? '';
+        $email = $_POST['email'] ?? '';
+
+        if (empty($username) || empty($password) || empty($email)) {
+            $error = 'All fields are required.';
+            require PROJECT_ROOT . '/views/auth/register.php';
+            return;
+        }
+
+        $user = new User($this->db);
+        if ($user->register($username, $password, $email)) {
+            header('Location: /');
+            exit;
+        } else {
+            $error = 'Registration failed. Please try again.';
+            require PROJECT_ROOT . '/views/auth/register.php';
+        }
+    }
+}
diff --git a/src/Controller/DashboardController.php b/src/Controller/DashboardController.php
new file mode 100644
index 0000000..a616fda
--- /dev/null
+++ b/src/Controller/DashboardController.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace Hpz937\BillReminder\Controller;
+
+class DashboardController {
+    public function viewDashboard() {
+        if (!isset($_SESSION['user_id'])) {
+            header('Location: /login');
+            exit;
+        }
+        require PROJECT_ROOT . '/views/dashboard.php';
+    }
+
+    public function viewSettings() {
+        if (!isset($_SESSION['user_id'])) {
+            header('Location: /login');
+            exit;
+        }
+        require PROJECT_ROOT . '/views/settings.php';
+    }
+}
diff --git a/src/Controller/HomeController.php b/src/Controller/HomeController.php
new file mode 100644
index 0000000..cd4c7b9
--- /dev/null
+++ b/src/Controller/HomeController.php
@@ -0,0 +1,8 @@
+<?php
+namespace Hpz937\BillReminder\Controller;
+
+class HomeController {
+    public function index() {
+        require PROJECT_ROOT . '/views/home.php';
+    }
+}
diff --git a/src/Database/SQLiteAdapter.php b/src/Database/SQLiteAdapter.php
index 32f9bcb..9f55f8b 100644
--- a/src/Database/SQLiteAdapter.php
+++ b/src/Database/SQLiteAdapter.php
@@ -1,21 +1,25 @@
-<?php
+<?php 
 
 namespace Hpz937\BillReminder\Database;
 
-use PDO;
-use PDOException;
+use Exception;
+use SQLite3;
 
 class SQLiteAdapter implements DatabaseInterface
 {
     private $connection;
 
+    /**
+     * Connect to the SQLite database
+     * 
+     * @return SQLite3
+     */
     public function connect()
     {
         if ($this->connection === null) {
             try {
-                $this->connection = new PDO('sqlite:' . __DIR__ . '/../../database.db');
-                $this->connection->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
-            } catch (PDOException $e) {
+                $this->connection = new SQLite3(__DIR__ . '/../../database.db');
+            } catch (Exception $e) {
                 // In a real application, you might want to use a more sophisticated error handling approach
                 die("Connection error: " . $e->getMessage());
             }
@@ -24,17 +28,35 @@ class SQLiteAdapter implements DatabaseInterface
         return $this->connection;
     }
 
+    /**
+     * Query the database and return the result
+     * 
+     * @param string $query
+     * @param array $params
+     * @return array|null
+     */
     public function query(string $query, array $params = [])
     {
         $stmt = $this->connect()->prepare($query);
 
-        if (!$stmt->execute($params)) {
-            // Again, consider a more sophisticated error handling in a real application
-            die("Query error: " . implode(", ", $stmt->errorInfo()));
+        foreach ($params as $key => $value) {
+            // var_dump($key, $value);
+            $stmt->bindValue($key, $value);
+        }
+
+        try {
+            // var_dump($stmt->getSQL(true));
+            $result = $stmt->execute();
+        } catch (Exception $e) {
+            die("Query error: " . $e->getMessage());
         }
 
         if (preg_match('/^(SELECT|SHOW|PRAGMA)/i', $query)) {
-            return $stmt->fetchAll(PDO::FETCH_ASSOC);
+            $output = [];
+            while ($row = $result->fetchArray(SQLITE3_ASSOC)) {
+                $output[] = $row;
+            }
+            return $output;
         }
 
         return null;
diff --git a/src/Routing/Router.php b/src/Routing/Router.php
new file mode 100644
index 0000000..4e39633
--- /dev/null
+++ b/src/Routing/Router.php
@@ -0,0 +1,26 @@
+<?php
+
+namespace Hpz937\BillReminder\Routing;
+
+class Router {
+    protected $routes = [];
+
+    public function register($method, $path, $action) {
+        $this->routes[$method][$path] = $action;
+    }
+
+    public function resolve($method, $uri) {
+        if (isset($this->routes[$method][$uri])) {
+            $action = $this->routes[$method][$uri];
+            if (is_array($action)) {
+                list($class, $method) = $action;
+                return (new $class)->$method();
+            }
+        }
+
+        // Handle 404 Not Found
+        http_response_code(404);
+        echo 'Page not found';
+    }
+}
+
diff --git a/src/User/User.php b/src/User/User.php
index 8735d82..91a1275 100644
--- a/src/User/User.php
+++ b/src/User/User.php
@@ -45,9 +45,9 @@ class User
 
         try {
             $user = $this->db->query($sql, $params);
-            if ($user && password_verify($password, $user[0]['password'])) {
+            if ($user && password_verify($password, $user['password'])) {
                 // Set session or token here as per your session management strategy
-                $_SESSION['user_id'] = $user[0]['id'];
+                $_SESSION['user_id'] = $user['id'];
                 return true;
             }
             return false;
diff --git a/views/dashboard.php b/views/dashboard.php
index a1a5078..9f4ed41 100644
--- a/views/dashboard.php
+++ b/views/dashboard.php
@@ -43,7 +43,7 @@ $content = function() { /* use ($bills) if fetching bills from the database */
                                 <span aria-hidden="true">&times;</span>
                             </button>
                         </div>
-                        <form action="/add-bill" method="post">
+                        <form id="addBillForm">
                             <div class="modal-body">
                                 <div class="form-group">
                                     <label for="description">Description</label>
diff --git a/views/layouts/app.php b/views/layouts/app.php
index cd41c60..db7ad10 100644
--- a/views/layouts/app.php
+++ b/views/layouts/app.php
@@ -21,6 +21,12 @@
     </nav>
 
     <div class="container">
+        <?php if (isset($error) && !empty($error)): ?>
+            <div class="alert alert-danger" role="alert">
+                <?php echo $error; ?>
+            </div>
+        <?php endif; ?>
+
         <?php if (isset($content) && is_callable($content)) $content(); ?>
     </div>