Title: Headers duplicates Last modified: June 18, 2021 --- # Headers duplicates * Resolved [dovich](https://wordpress.org/support/users/dovich/) * (@dovich) * [4 years, 11 months ago](https://wordpress.org/support/topic/headers-duplicates/) * In `https://wordpress.org/support/plugin/wp-rest-cache/` line 361 * rest_send_cors_headers() actually duplicates the headers set in my nginx config. Need some option on dashboard to prevent sending headers from plugin. Viewing 15 replies - 1 through 15 (of 15 total) * Plugin Author [Richard Korthuis](https://wordpress.org/support/users/rockfire/) * (@rockfire) * [4 years, 11 months ago](https://wordpress.org/support/topic/headers-duplicates/#post-14577581) * Hi [@dovich](https://wordpress.org/support/users/dovich/) * Thank you for using our plugin! * The `rest_send_cors_headers()` function is an almost exact copy of the same function from the WordPress core (`wp-includes/rest-api.php`). So if you are having problems with our plugin I would think you would also have problems when using the default REST API provided by WordPress? And if so I would say it is a problem with your nginx configuration? Could you confirm you are having the same problems when not using our plugin? * Thread Starter [dovich](https://wordpress.org/support/users/dovich/) * (@dovich) * [4 years, 11 months ago](https://wordpress.org/support/topic/headers-duplicates/#post-14591379) * Hi, Richard. * Thank you for your plugin! * I completely forgot tell you about a “little” detail – default WP rest headers is disbled, and it’s possible directly from my code: `remove_filter( 'rest_pre_serve_request',' rest_send_cors_headers' );` * So there is no problem with my nginx configuration, and all headers are controled by nginx (production necessity). * I just asked you about the possibility to somehow disable sending headers in your plugin – be it a filter or an option in the admin panel. * Thank you. * Plugin Author [Richard Korthuis](https://wordpress.org/support/users/rockfire/) * (@rockfire) * [4 years, 10 months ago](https://wordpress.org/support/topic/headers-duplicates/#post-14639818) * Hi [@dovich](https://wordpress.org/support/users/dovich/) * Sorry for the late reply. * Ok, that is clear. We will add a filter in our next release, allowing you to disable the sending of the CORS headers (`wp_rest_cache/disable_cors_headers`). * Thread Starter [dovich](https://wordpress.org/support/users/dovich/) * (@dovich) * [4 years, 10 months ago](https://wordpress.org/support/topic/headers-duplicates/#post-14668012) * Thank You! * Plugin Author [Richard Korthuis](https://wordpress.org/support/users/rockfire/) * (@rockfire) * [4 years, 8 months ago](https://wordpress.org/support/topic/headers-duplicates/#post-14874429) * Hi [@dovich](https://wordpress.org/support/users/dovich/) * Sorry, it took a bit longer than intended, but we just released a new version of our plugin which includes the mentioned filter. * Thread Starter [dovich](https://wordpress.org/support/users/dovich/) * (@dovich) * [4 years, 8 months ago](https://wordpress.org/support/topic/headers-duplicates/#post-14880933) * Thank you, Richard. I really appreciate your work. * [lorenzocroccolino](https://wordpress.org/support/users/lorenzocroccolino/) * (@lorenzocroccolino) * [4 years, 7 months ago](https://wordpress.org/support/topic/headers-duplicates/#post-15004577) * Hi, I appreciate a lot the CORS update but unfortunately, I am not able to make it works properly. I’m adding the line `apply_filters( 'wp_rest_cache/disable_cors_headers', true )` inside my functions.php but nothing change, I still have a header duplication. * Can you kindly explain what I am doing wrong? Thanks a lot. * Plugin Author [Richard Korthuis](https://wordpress.org/support/users/rockfire/) * (@rockfire) * [4 years, 7 months ago](https://wordpress.org/support/topic/headers-duplicates/#post-15006732) * Hi [@lorenzocroccolino](https://wordpress.org/support/users/lorenzocroccolino/) * Thank you for using our plugin! * First of all you have to use the function `add_filter` instead of `apply_filters` and second you have to actually return a value. So in your case you could use this: `add_filter( 'wp_rest_cache/disable_cors_headers', '__return_true' );` - This reply was modified 4 years, 7 months ago by [Richard Korthuis](https://wordpress.org/support/users/rockfire/). * [matteocollina](https://wordpress.org/support/users/matteocollina/) * (@matteocollina) * [4 years, 7 months ago](https://wordpress.org/support/topic/headers-duplicates/#post-15006857) * Hi [@rockfire](https://wordpress.org/support/users/rockfire/) * I’ve just tried your snippet but it doesn’t work, I received two header **access- control-allow-origin** * ``` function initCors( $value , $requestUri = null ) { header_remove("Access-Control-Allow-Origin"); return $value; } add_action( 'rest_api_init', function() { remove_filter( 'rest_pre_serve_request','rest_send_cors_headers' ); add_filter( 'rest_pre_serve_request', initCors); }, 15 ); add_filter( 'wp_rest_cache/disable_cors_headers', '__return_false' ); ``` * Plugin Author [Richard Korthuis](https://wordpress.org/support/users/rockfire/) * (@rockfire) * [4 years, 7 months ago](https://wordpress.org/support/topic/headers-duplicates/#post-15006910) * [@matteocollina](https://wordpress.org/support/users/matteocollina/) * Oops `'__return_false'` should have been `'__return_true'`, my mistake. I have changed my previous message to correct this error. * [matteocollina](https://wordpress.org/support/users/matteocollina/) * (@matteocollina) * [4 years, 7 months ago](https://wordpress.org/support/topic/headers-duplicates/#post-15006958) * [@rockfire](https://wordpress.org/support/users/rockfire/) sorry but it doesn’t work also with `__return_true` * Plugin Author [Richard Korthuis](https://wordpress.org/support/users/rockfire/) * (@rockfire) * [4 years, 7 months ago](https://wordpress.org/support/topic/headers-duplicates/#post-15006989) * Hi [@matteocollina](https://wordpress.org/support/users/matteocollina/) * Did you clear your cache before retrying (after adding the code)? * [matteocollina](https://wordpress.org/support/users/matteocollina/) * (@matteocollina) * [4 years, 7 months ago](https://wordpress.org/support/topic/headers-duplicates/#post-15007069) * Hi [@rockfire](https://wordpress.org/support/users/rockfire/) . * Yes I cleared the entire cache. * I follow this steps: * 1- Added `add_filter( 'wp_rest_cache/disable_cors_headers', '__return_true' );` to _plugin.php_ 2- Cleared the cache with _Clear Rest Cache_ button. 3- Get the URL the first time and it works without cache (I have in the response headers only `access-control-allow-origin: *`) 4- Get the same URL the second time and it doesn’t work (I have two `access-control-allow-origin` header: **\*** and ** [http://www.mydomain.com](http://www.mydomain.com)**) - This reply was modified 4 years, 7 months ago by [matteocollina](https://wordpress.org/support/users/matteocollina/). * Plugin Author [Richard Korthuis](https://wordpress.org/support/users/rockfire/) * (@rockfire) * [4 years, 7 months ago](https://wordpress.org/support/topic/headers-duplicates/#post-15007717) * [@matteocollina](https://wordpress.org/support/users/matteocollina/) * It is no good when you try to answer questions too quickly 😉 One small detail I forgot to mention is that you cannot use this filter from a theme or plugin, sorry for that. Our plugin loads as a must use plugin in order to be able to hook into the REST API as soon as possible and skip any loading of themes and/ or plugins is a cache is found. Because of this your code isn’t executed if a cache is found, so to use this hook you would have to create a mu-plugin which is loaded before our mu-plugin (i.e. it should alfabetically be before `wp-rest- cache`). So the simplest solution would be to create a file `disable-cors-headers. php` in the directory /wp-content/mu-plugins and put the `add_filter` code inside it. * [matteocollina](https://wordpress.org/support/users/matteocollina/) * (@matteocollina) * [4 years, 7 months ago](https://wordpress.org/support/topic/headers-duplicates/#post-15011105) * [@rockfire](https://wordpress.org/support/users/rockfire/) You right man! It works, thank you very much! Viewing 15 replies - 1 through 15 (of 15 total) The topic ‘Headers duplicates’ is closed to new replies. * ![](https://ps.w.org/wp-rest-cache/assets/icon-256x256.png?rev=3328849) * [WP REST Cache](https://wordpress.org/plugins/wp-rest-cache/) * [Frequently Asked Questions](https://wordpress.org/plugins/wp-rest-cache/#faq) * [Support Threads](https://wordpress.org/support/plugin/wp-rest-cache/) * [Active Topics](https://wordpress.org/support/plugin/wp-rest-cache/active/) * [Unresolved Topics](https://wordpress.org/support/plugin/wp-rest-cache/unresolved/) * [Reviews](https://wordpress.org/support/plugin/wp-rest-cache/reviews/) * 15 replies * 4 participants * Last reply from: [matteocollina](https://wordpress.org/support/users/matteocollina/) * Last activity: [4 years, 7 months ago](https://wordpress.org/support/topic/headers-duplicates/#post-15011105) * Status: resolved