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gistfile1.txt

function json_rest_api_multisites_api_init() {
    global $json_rest_api_multisites_api_site;

    $json_rest_api_multisites_api_site = new JsonRESTAPIMultiSites_API_Site();
    add_filter('json_endpoints', array($json_rest_api_multisites_api_site, 'register_routes'));
}

add_action( 'wp_json_server_before_serve', 'json_rest_api_multisites_api_init');

class JsonRESTAPIMultiSites_API_Site {
    public function register_routes($routes) {
        $routes['/sites'] = array(
            array(array($this, 'get_site_details'), WP_JSON_Server::READABLE),
        );
        return $routes;
    }

    public function get_sites() {
        return wp_get_sites();
        $sites = wp_get_sites();
        $sites_with_names = array();
        foreach( $sites as $key, $value) {
        $sites_with_names[] = get_blog_details($value['blog_id']);
        }
        return $sites_with_names;
    }
        
}