Extending

namespace local_wayfinder\local\wayfinder\commands\myfeature;
 
use local_wayfinder\local\wayfinder\items\command;
use local_wayfinder\local\wayfinder\actions\redirect;
 
class mycommand extends command {
    public function __construct(renderer $renderer) {
        parent::__construct($renderer, 'My Command', 'Does something cool');
        $this->set_keywords(['cool', 'thing']);
        $this->set_action(new redirect('https://moodle.local/my/cool/page.php'));
    }
 
    public function check_access(): bool {
        return has_capability('some/capability', $this->get_context());
    }
}

namespace local_wayfinder\local\wayfinder\groups\mygroup;
 
use local_wayfinder\local\wayfinder\items\group;
 
class mygroup extends group {
    public function __construct(renderer $renderer) {
        $items = [];
        // Build items from some data source.
        $items[] = new \local_wayfinder\local\wayfinder\commands\myfeature\mycommand($renderer);
        parent::__construct($renderer, 'My Group', $items);
    }
}

namespace local_wayfinder\local\wayfinder\actions\myaction;
 
use local_wayfinder\local\wayfinder\action;
 
class myaction extends action {
    public function __construct(
        private readonly string $url,
    ) {}
 
    protected static function get_id(): string {
        return 'myaction';
    }
 
    public function jsonSerialize(): array {
        return parent::jsonSerialize() + ['url' => $this->url];
    }
}