diff --git a/core/classes/Endpoints/EndpointBase.php b/core/classes/Endpoints/EndpointBase.php
index 1614f5b2a4..356bcf7788 100644
--- a/core/classes/Endpoints/EndpointBase.php
+++ b/core/classes/Endpoints/EndpointBase.php
@@ -87,4 +87,14 @@ final public function getAuthType(): string
      * @return bool
      */
     abstract public function isAuthorised(Nameless2API $api): bool;
+
+    /**
+     * Allow auth methods to add custom params to endpoint.
+     *
+     * @return array Custom endpoint params
+     */
+    public function customParams(): array
+    {
+        return [];
+    }
 }
diff --git a/core/classes/Endpoints/Endpoints.php b/core/classes/Endpoints/Endpoints.php
index f61c2e13dc..5caa43d41d 100644
--- a/core/classes/Endpoints/Endpoints.php
+++ b/core/classes/Endpoints/Endpoints.php
@@ -63,15 +63,15 @@ public function handle(string $route, string $method, Nameless2API $api): void
                     }
 
                     $reflection = new ReflectionMethod($endpoint, 'execute');
-                    if ($reflection->getNumberOfParameters() !== (count($vars) + 1)) {
-                        throw new InvalidArgumentException("Endpoint's 'execute()' method must take " . (count($vars) + 1) . ' arguments. Endpoint: ' . $endpoint->getRoute());
+                    if ($reflection->getNumberOfParameters() !== (count($endpoint->customParams()) + count($vars) + 1)) {
+                        throw new InvalidArgumentException("Endpoint's 'execute()' method must take " . (count($endpoint->customParams()) + count($vars) + 1) . ' arguments. Endpoint: ' . $endpoint->getRoute());
                     }
 
                     $endpoint->execute(
                         $api,
-                        ...array_map(function ($type, $value) use ($api) {
+                        ...array_merge($endpoint->customParams(), array_map(function ($type, $value) use ($api) {
                             return $this::transform($api, $type, $value);
-                        }, array_keys($vars), $vars)
+                        }, array_keys($vars), $vars))
                     );
 
                     return;