URL should take into account the app URL as well.

Author: ghilead

app/views/grape_swagger_rails/application/index.html.erb

@@ -10,7 +10,7 @@
 	  var options = $("html").data('swagger-options');
 
     window.swaggerUi = new SwaggerUi({
-      url: options.url,
+      url: options.app_url + options.url,
       dom_id:"swagger-ui-container",
       supportHeaderParams: true,
       headers: options.headers,