---
title: Configure a notification listener using the React Native SDK
slug: feature-experimentation/docs/set-up-notification-listener-reactnative-prior-to-v4
docTags: 
createdAt: 2026-08-05T20:39:54.000Z
---

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 information about notification listener types and use cases, see [Notification listeners](docId:0d__cjuKECyJGqgTV0_5e).

:::hint{type="info"}
**Note**
The follow code examples assume you have already [initialized the React Native SDK](docId\:LXmOS7VyTsw0iZDvX7GzL) and have created an `optimizelyClient` instance.
:::

## Add and remove all notification listeners

The following example code 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.

```javascript
import { enums } from '@optimizely/react-sdk';

// Remove Notification Listener
optimizelyClient.notificationCenter.removeNotificationListener(notificationId);

// Remove All Notification Listeners
optimizelyClient.notificationCenter.clearAllNotificationListeners();

// Remove all Notification Listeners of a certain type
optimizelyClient.notificationCenter.clearNotificationListeners(enums.NOTIFICATION_TYPES.DECISION);
```

## Configure each type of notification listener

The following example code shows how to configure each type of notification listener.

```javascript
import { enums } from '@optimizely/react-sdk';
// import your third-party analytics integration here

///////////////////////////////////////////
// SET UP DECISION NOTIFICATION LISTENER //
///////////////////////////////////////////

const onDecision = ({ type, userId, attributes, decisionInfo }) => {
  // Add a DECISION Notification Listener for type FLAG
  if (type === 'flag') {
    // Access information about feature, for example, key and enabled status
    console.log(decisionInfo['flagKey']);
    console.log(decisionInfo['enabled']);
    console.log(decisionInfo['decisionEventDispatched']);
    // Send data to analytics provider here
  }
}

const notificationId = optimizelyClient.notificationCenter.addNotificationListener(enums.NOTIFICATION_TYPES.DECISION, onDecision);


////////////////////////////////////////////
// SET UP LOG EVENT NOTIFICATION LISTENER //
////////////////////////////////////////////

const onLogEvent = (logEvent) => {
  // process the logEvent object here (send to analytics provider, audit/inspect data)
}

optimizelyClient.notificationCenter.addNotificationListener(enums.NOTIFICATION_TYPES.LOG_EVENT, onLogEvent);


////////////////////////////////////////////////////
// SET UP OPTIMIZELY CONFIG NOTIFICATION LISTENER //
////////////////////////////////////////////////////

// listen to OPTIMIZELY_CONFIG_UPDATE to get updated data
// You will get notifications whenever the datafile is updated except for SDK initialization
const onConfigUpdateListener = () => {
  const config = optimizelyClient.getOptimizelyConfig()
}

optimizelyClient.notificationCenter.addNotificationListener(enums.NOTIFICATION_TYPES.OPTIMIZELY_CONFIG_UPDATE, onConfigUpdateListener);


////////////////////////////////////////
// SET UP TRACK NOTIFICATION LISTENER //
////////////////////////////////////////

const onTrack = (event) => {
  // process the event here (send to analytics provider, audit/inspect data)
}

optimizelyClient.notificationCenter.addNotificationListener(enums.NOTIFICATION_TYPES.TRACK, onTrack);
```