add custom post type to WP-API

cpt.php

function wpsd_add_events_args() {
    global $wp_post_types;

    $wp_post_types['incsub_wiki']->show_in_rest = true;
    $wp_post_types['incsub_wiki']->rest_base = 'wiki';
    $wp_post_types['incsub_wiki']->rest_controller_class = 'WP_REST_Posts_Controller';
}
add_action( 'init', 'wpsd_add_events_args', 30 );