Since WordPress 4.7 the filter argument for any post endpoint was removed. This plugin restores the filter parameter for websites that were previously using it. Usage Use the filter parameter on any Post, or Custom Post Type endpoint such as /wp/v2/posts or /wp/v2/cpt as an array of WP_Query argument. ACF values are also supported. Default Post Type fetch( ‘https://domain.com/wp-json/wp/v2/posts?filter[meta_key]=acfkey&filter[meta_value]=acfvalue’); Filter Users fetch( ‘https://domain.com/wp-json/wp/v2/users?filter[meta_key]=acfkey&filter[meta_value]=acfvalue’); Custom Post Type fetch( ‘https://domain.com/wp-json/wp/v2/cars?filter[meta_key]=currency&filter[meta_value]=AUD’); // here ‘cars’ is the endpoint for CPT Advanced Custom Field fetch( ‘https://domain.com/wp-json/wp/v2/cars?filter[meta_key]=price&filter[meta_compare]=