---
title: "User Data"
slug: "user-data-react-native-engage"
updated: 2026-04-13T15:36:06Z
published: 2026-04-13T15:36:06Z
canonical: "docs.mapp.com/user-data-react-native-engage"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mapp.com/llms.txt
> Use this file to discover all available pages before exploring further.

# User Data

## Introduction

The plugin provides methods to identify devices, store custom attributes, manage tags, track events, and handle logout. Most methods are available on both platforms unless noted.

## Device Alias

An alias links the device to a known user identity in Mapp Engage.

```javascript
// Set alias
Mapp.setAlias('user@example.com');

// Set alias and resend previously stored custom attributes to the backend
Mapp.setAlias('user@example.com', true);

// Get current alias
const alias = await Mapp.getAlias();
```

## Custom Attributes

### Set

```javascript
// Set multiple attributes at once
Mapp.setAttributes({ plan: 'premium', region: 'EU' });

// Set a single string attribute
Mapp.setAttributeString('plan', 'premium');

// Set a single integer attribute
Mapp.setAttributeInt('login_count', 5);
```

### Get

```javascript
const values = await Mapp.getAttributes(['plan', 'region']);
const plan = await Mapp.getAttributeStringValue('plan');
```

### Remove (Android only)

```javascript
Mapp.removeAttribute('plan');
```

### Increment Numeric Attribute (iOS only)

```javascript
Mapp.incrementNumericKey('purchase_count', 1);
```

## Tags

```javascript
Mapp.addTag('premium');
Mapp.removeTag('trial');
const tags = await Mapp.getTags();
```

## Custom Events

Use the `CustomEvent` class to build and send tracking events to the Mapp backend.

```javascript
import CustomEvent from 'react-native-mapp-plugin/CustomEvent';
import { Mapp } from 'react-native-mapp-plugin';

const event = new CustomEvent('purchase', 49.99);
event.transactionId = 'order-12345';
event.addProperty('currency', 'USD');
event.addProperty('category', 'subscription');

await Mapp.addCustomEvent(event);
```

`CustomEvent` constructor and properties:

- `name` (string, required): Event name used for identification in Mapp Engage.
- `value` (number, optional): Numeric value associated with the event.
- `transactionId` (string): Prevents duplicate events on the backend.
- `addProperty(name, value)`: Attaches metadata. Value may be string, number, boolean, or string[].

## Log Out

Clears the user identity from the device. Pass `true` to keep push notifications active after logout.

```javascript
Mapp.logOut(true);
```