---
title: Configure the React Native SDK event dispatcher
slug: feature-experimentation/docs/configure-the-react-native-sdk-event-dispatcher
docTags: 
createdAt: 2026-08-05T20:39:55.000Z
---

The Optimizely SDKs make HTTP requests for every [decision event or conversion event](docId\:SzVcfUMHk3IKycnEjgjbq) that gets triggered. The React Native SDK has a built-in **event dispatcher** for handling these events.

## Minimum SDK version

v4.0.0+

For versions 3.x and earlier, see [React Native SDK prior to v4](docId\:Br6HotyqTASM7xPBdkHNB).

## Description

In v4, event processing is **opt-in**. You must pass an `eventProcessor` to `createInstance` to enable event dispatching. The SDK provides two built-in event processor factories:

| Factory                                                     | Use case                           |
| ----------------------------------------------------------- | ---------------------------------- |
| `createBatchEventProcessor({ batchSize?, flushInterval? })` | Batches events before dispatching. |
| `createForwardingEventProcessor()`                          | Forwards each event immediately.   |

Both processors use the SDK's built-in event dispatcher by default.

## Custom event dispatcher

You can customize the event dispatcher for more control over how the SDK sends events so that it scales to the volumes handled by your application. In v4, the `EventDispatcher` interface uses Promises instead of callbacks:

```typescript
export type EventDispatcherResponse = {
  statusCode?: number;
};

export interface EventDispatcher {
  dispatchEvent(event: LogEvent): Promise<EventDispatcherResponse>;
}
```

Pass a custom event dispatcher to the event processor factory:

```javascript
import {
  createInstance,
  createPollingProjectConfigManager,
  createBatchEventProcessor,
} from '@optimizely/react-sdk';

const customEventDispatcher = {
  dispatchEvent(event) {
    return fetch(event.url, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(event.params),
    }).then((res) => ({ statusCode: res.status }));
  },
};

const optimizely = createInstance({
  projectConfigManager: createPollingProjectConfigManager({
    sdkKey: 'YOUR_SDK_KEY',
  }),
  eventProcessor: createBatchEventProcessor({
    eventDispatcher: customEventDispatcher,
  }),
});
```

:::hint{type="warning"}
**Important**
If you are using a custom event dispatcher, do not modify the event payload returned from Optimizely. Modifying this payload will alter your results.
:::

## Disable event dispatching

To disable sending all events to Optimizely's results backend, simply omit the `eventProcessor` parameter when calling `createInstance`. In v4, no events are dispatched by default.