Notification listeners trigger a callback function that you define when certain actions are triggered in the SDK.
The most common use case is to send a stream of all feature flag decisions to an analytics provider or to an internal data warehouse to join it with other data that you have about your users.
## Notification listener types
For more information about notification listener types and use cases, see [Notification listeners](🔗).
For code samples, see the following sections.
## Add and remove all notification listeners
The example code below shows how to add a listener, remove a listener, remove all listeners of a specific type (such as all decision listeners), and remove all listeners.
## Set up each type of notification listener
The example code below shows how to set up each type of notification listener.