> For the complete documentation index, see [llms.txt](https://docs.minical.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.minical.io/build-an-extension/build-your-first-extension/helper.md).

# Helper

Each helper file is simply a collection of functions in a particular category. For example, we have a booking\_list\_helper.php file.

```php
<?PHP
//file name booking_list_helper.php
function custom_helper($data){
    // start writing code here   
}
?>
```

**Loading of booking\_list\_helper.php**

For loading helper file go to the autoload.php under config folder of your extension add helper file in the array, use $extension\_helper variable. you can add multiple helper files into this array, they will be loaded automatically by my\_controller.

```php
//file name autoload.php
$extension_helper  = array(
                      'booking_list_helper'
                     );
```