> For the complete documentation index, see [llms.txt](https://docs.kuusamo.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.kuusamo.org/technical/custom-error-handling.md).

# Custom error handling

If you want to log errors to an application monitoring system, you can use a custom error handler.

Register this in `public/index.php` before you cann the `kuusamo` function.

```
Kuusamo\Vle\Exception\ErrorHandler::register(function($exception) {
    var_dump($exception->getMessage());
});
```

Foe example, lets say you wanted to integrate Rollbar. Install the Rollbar library using Composer and then add the following to your `index.php` file.

```
Rollbar\Rollbar::init([
    'access_token' => 'your_access_token',
    'environment' => 'production',
]);

Kuusamo\Vle\Exception\ErrorHandler::register(function($exception) {
    Rollbar\Rollbar::report_exception($exception);
});
```

Note that custom error handlers will only run when the project is in `production` mode. During development, the exception is presented to the developer.