Add configuration options for serialization

**Feature request**
It would be great to have notifications for auth.

**Use case**
Many users need this functionality for production deployments.

**Implementation idea**
Add a new config option `enable_notifications` with default `false`.

No file, test, or entry point is named. Start by locating the existing configuration handling and authentication notification path, then check how default values are represented; done means the new enable_notifications option defaults to false and supports the requested notification behavior.

Written by the indexing model from the issue text.