How to extend the error and exception handling

If you want to register your own error or exception handler:

  1. Create a corresponding class in your extension

  2. Override the Core defaults for productionExceptionHandler, debugExceptionHandler or errorHandler in config/system/additional.php:

    config/system/additional.php | typo3conf/system/additional.php
    $GLOBALS['TYPO3_CONF_VARS']['SYS']['errorHandler'] = \Vendor\Ext\Error\MyOwnErrorHandler::class;
    $GLOBALS['TYPO3_CONF_VARS']['SYS']['debugExceptionHandler'] = \Vendor\Ext\Error\MyOwnDebugExceptionHandler::class;
    $GLOBALS['TYPO3_CONF_VARS']['SYS']['productionExceptionHandler'] = \Vendor\Ext\Error\MyOwnProductionExceptionHandler::class;


We use config/system/additional.php and not ext_localconf.php in the extension (as previously documented) because that will be executed after the error / exception handlers are initialized in the bootstrap process.

An error or exception handler class must register an error (exception) handler in its constructor. Have a look at the files in EXT:core/Classes/Error/ to see how this should be done.

If you want to use the built-in error and exception handling but extend it with your own functionality, derive your class from the error and exception handling classes shipped with TYPO3.

Example Debug Exception Handler

This uses the default Core exception handler DebugExceptionHandler and overrides some of the functionality:

namespace Vendor\SomeExtension\Error;

class PostExceptionsOnTwitter extends \TYPO3\CMS\Core\Error\DebugExceptionHandler
    public function echoExceptionWeb(Exception $exception)

    public function postExceptionsOnTwitter($exception)
        // do it ;-)
config/system/additional.php | typo3conf/system/additional.php
$GLOBALS['TYPO3_CONF_VARS']['SYS']['debugExceptionHandler'] = \Vendor\SomeExtension\Error\PostExceptionsOnTwitter::class;