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docs/configuration/router.md

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+
+## Router service
+
+Router service is using well-known [FastRoute](https://github.com/nikic/FastRoute) library. There is no need to change this service unless you're extending the script.
+
+The router uses unique query parameter ```?r=``` to pass the route info. Because of this feature, this (single-page) application does not require rewrite rules, .htaccess or similar tweaks.
+
+Example routes:
+
+- ```http://example.com/?r=/some/route&param1=val1&param2=val2```
+- ```http://example.com/?r=/user/{user_id}&param1=val1```
+
+
+## Routes file
+
+Routes file is located here ```/backend/Controllers/routes.php```. Each route in the routes array looks like this:
+
+
+```
+    [
+        'route' => [
+            'GET', '/download/{path_encoded}', '\Filegator\Controllers\DownloadController@download',
+        ],
+        'roles' => [
+            'guest', 'user', 'admin',
+        ],
+        'permissions' => [
+            'download',
+        ],
+    ],
+```
+
+As you can in the example, you can assign required user roles and permissions for each route.
+
+## Controllers
+
+Since FileGator is using an awesome dependency injection [container](https://github.com/PHP-DI/PHP-DI) you can type-hint dependencies directly in your controllers. 
+
+You can also mix route parameters and dependencies in any order like in this example:
+
+```
+
+    public function __construct(Config $config, Session $session, AuthInterface $auth, Filesystem $storage)
+    {
+      // ...
+    }
+
+    public function download($path_encoded, Request $request, Response $response, StreamedResponse $streamedResponse)
+    {
+      // ...
+    }
+```