diff --git a/.envDefault b/.envDefault
index 8290d4f..1fa763a 100644
--- a/.envDefault
+++ b/.envDefault
@@ -1,3 +1,5 @@
 displayError=true
 logErrors=true
 logErrorDetails=true
+RequestLimit=1
+RequestLimitTimeout=10000
diff --git a/app/ErrorHandler/CustomHtmlErrorRenderer.php b/app/ErrorHandler/CustomHtmlErrorRenderer.php
new file mode 100644
index 0000000..c2238aa
--- /dev/null
+++ b/app/ErrorHandler/CustomHtmlErrorRenderer.php
@@ -0,0 +1,108 @@
+<?php
+
+/**
+ * Slim Framework (https://slimframework.com)
+ *
+ * @license https://github.com/slimphp/Slim/blob/4.x/LICENSE.md (MIT License)
+ */
+
+declare(strict_types=1);
+
+namespace App\ErrorHandler;
+
+use Slim\Error\AbstractErrorRenderer;
+use Throwable;
+
+use function get_class;
+use function htmlentities;
+use function sprintf;
+
+/**
+ * Default Slim application HTML Error Renderer
+ */
+class CustomHtmlErrorRenderer extends AbstractErrorRenderer
+{
+  /**
+   * @param Throwable $exception
+   * @param bool      $displayErrorDetails
+   * @return string
+   */
+  public function __invoke(Throwable $exception, bool $displayErrorDetails): string
+  {
+    if ($displayErrorDetails) {
+      $html = '<p>The application could not run because of the following error:</p>';
+      $html .= '<h2>Details</h2>';
+      $html .= $this->renderExceptionFragment($exception);
+    } else {
+      $html = "<p><b>{$exception->getMessage()}</b><br>{$this->getErrorDescription($exception)}</p>";
+    }
+
+    return $this->renderHtmlBody($this->getErrorTitle($exception), $html);
+  }
+
+  /**
+   * @param Throwable $exception
+   * @return string
+   */
+  private function renderExceptionFragment(Throwable $exception): string
+  {
+    $html = sprintf('<div><strong>Type:</strong> %s</div>', get_class($exception));
+
+    $code = $exception->getCode();
+    if ($code !== null) {
+      $html .= sprintf('<div><strong>Code:</strong> %s</div>', $code);
+    }
+
+    $message = $exception->getMessage();
+    if ($message !== null) {
+      $html .= sprintf('<div><strong>Message:</strong> %s</div>', htmlentities($message));
+    }
+
+    $file = $exception->getFile();
+    if ($file !== null) {
+      $html .= sprintf('<div><strong>File:</strong> %s</div>', $file);
+    }
+
+    $line = $exception->getLine();
+    if ($line !== null) {
+      $html .= sprintf('<div><strong>Line:</strong> %s</div>', $line);
+    }
+
+    $trace = $exception->getTraceAsString();
+    if ($trace !== null) {
+      $html .= '<h2>Trace</h2>';
+      $html .= sprintf('<pre>%s</pre>', htmlentities($trace));
+    }
+
+    return $html;
+  }
+
+  /**
+   * @param string $title
+   * @param string $html
+   * @return string
+   */
+  public function renderHtmlBody(string $title = '', string $html = ''): string
+  {
+    return sprintf(
+      '<html>' .
+        '   <head>' .
+        "       <meta http-equiv='Content-Type' content='text/html; charset=utf-8'>" .
+        '       <title>%s</title>' .
+        '       <style>' .
+        '           body{margin:0;padding:30px;font:12px/1.5 Helvetica,Arial,Verdana,sans-serif}' .
+        '           h1{margin:0;font-size:48px;font-weight:normal;line-height:48px}' .
+        '           strong{display:inline-block;width:65px}' .
+        '       </style>' .
+        '   </head>' .
+        '   <body>' .
+        '       <h1>%s</h1>' .
+      '       <div>%s</div>' .
+        '   </body>' .
+        '</html>',
+      $title,
+      $title,
+      $html
+    );
+  }
+}
diff --git a/app/Kernel.php b/app/Kernel.php
index 58726fa..afda506 100644
--- a/app/Kernel.php
+++ b/app/Kernel.php
@@ -2,6 +2,7 @@
 
 namespace App;
 
+use App\ErrorHandler\CustomHtmlErrorRenderer;
 use App\Middlewares\ThrottleMiddleware;
 use Dotenv\Dotenv;
 use Dotenv\Exception\InvalidPathException;
@@ -51,6 +52,8 @@ class Kernel
       env('logErrors', false),
       env('logErrorDetails', false)
     );
+    $errorHandler = $errorMiddleware->getDefaultErrorHandler();
+    $errorHandler->registerErrorRenderer('text/html', CustomHtmlErrorRenderer::class);
   }
 
   private static function loadEnv()
@@ -69,7 +72,7 @@ class Kernel
 
   public static function env(string $key, $default = null)
   {
-    $value = getenv($key);
+    $value = self::$env[$key] ?? $default;
 
     if ($value === false) {
       return $default;
@@ -93,10 +96,6 @@ class Kernel
         return;
     }
 
-    // if (Str::startsWith($value, '"') && Str::endsWith($value, '"')) {
-    //   return substr($value, 1, -1);
-    // }
-
     return $value;
   }
 
diff --git a/app/Middlewares/ThrottleMiddleware.php b/app/Middlewares/ThrottleMiddleware.php
index 0b12206..5dc8384 100644
--- a/app/Middlewares/ThrottleMiddleware.php
+++ b/app/Middlewares/ThrottleMiddleware.php
@@ -5,6 +5,7 @@ namespace App\Middlewares;
 use Psr\Http\Message\ServerRequestInterface as Request;
 use Psr\Http\Server\RequestHandlerInterface as RequestHandler;
 use GuzzleHttp\Psr7\Response;
+use Slim\Exception\HttpForbiddenException;
 use Stiphle\Throttle\LeakyBucket;
 
 class ThrottleMiddleware
@@ -23,8 +24,12 @@ class ThrottleMiddleware
     //! Enable APC in Laragon https://forum.laragon.org/topic/1245/regarding-caching-plugin-availability/4
     $storage = new \Stiphle\Storage\Apcu();
     $throttle->setStorage($storage);
-    // limit to 1 per second
-    $throttle->throttle('api.request', 1, 10000);
+    // limit to 1 per second by default
+    $estimate = $throttle->getEstimate('api.request', env('RequestLimit', 1), env('RequestLimitTimeout', 1000));
+    if ($estimate > 1000) {
+      throw new HttpForbiddenException($request, 'Too many requests');
+    }
+    $throttle->throttle('api.request', env('RequestLimit', 1), env('RequestLimitTimeout', 1000));
     return $handler->handle($request);
   }
 }