I think it is very cool openresty works with lua instead of javascript. But the given example lets me wonder about its practical use:<p><i>Suppose before forwarding the data POSTed to your application you want to do certain checks on the data so that you can be sure that your application receives only the clean refined data to operate upon. (...) So your application layer can focus on working upon it without worrying about cleansing it first.</i><p>I would think that dealing with incorrect data should be handled by the application rather than nginx. If you want to expose your application via other means it means you don&#x27;t have to duplicate your validation logic. Think also about giving feedback about the incorrect POST-data, I think your application is better suited to provide that, as it can return a <i>&lt;form&gt;</i> with carefully placed messages for instance.