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Notification listeners

Notification listeners let you programmatically observe and act on various events that occur within the SDK in Optimizely Full Stack Flags version.

Notification listeners:

  • Give you flexibility in implementing custom integrations with analytics providers.
  • Enable integrations by passing data to external services.

Here are a few examples for using notification listeners:

  • Send data to an analytics service and report feature flag decision data, for example, report that user_123 was assigned to variation A.
  • Use SDK events to send alerts to data monitoring tools like New Relic and Datadog to visualize better how A/B tests affect service-level metrics.
  • Pass all events to an external data tier, like a data warehouse, for additional processing and to leverage business intelligence tools.
  • Re-initialize your SDK to quickly retrieve updated feature flag configuration data for your business-critical features.

The listeners work by triggering a callback function that you define and provide at runtime.

The following methods or lifecycle events trigger notification listeners if you have implemented the listener:

For notification listeners triggered by older methods such as Is Feature Enabled and Activate, see an earlier version of this page.

MethodNotification listener invoked
Decide methodsInvoke the DECISION notification listener if this listener is enabled.
Track EventInvokes the TRACK notification listener if this listener is enabled.
Important! This method will not call the TRACK notification listener when the specified event key is invalid
SDK Lifecycle eventNotification listener invoked
event batch flushedInvokes the LOGEVENT notification listener if this listener is enabled
new datafile retrievedInvokes the OPTIMIZELYCONFIGUPDATE notification listener if this listener is enabled.

For more information about each listener type, see:

Decision notification listener
Log event notification listener
optimizelyConfig update notification listener
Track notification listener


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