---
title: "Secure Instant sync in React Native | Nutrient authentication guide"
canonical_url: "https://www.nutrient.io/guides/react-native/instant-synchronization/authentication/"
md_url: "https://www.nutrient.io/guides/react-native/instant-synchronization/authentication.md"
last_updated: "2026-06-09T10:24:29.190Z"
description: "Authenticate your React Native client with Document Engine using JWTs. Learn to generate tokens and initialize the Nutrient Instant viewer for secure access."
---

# Client authentication in PSPDFKit Instant

To use Nutrient Instant for React Native, authenticate your client with your running Document Engine instance. This can be done by [generating a JSON Web Token (JWT)](https://www.nutrient.io/guides/document-engine/viewer/client-authentication/generate-a-jwt.md) and sending it to the client. In most cases, your backend application will generate and send the JWT to the client. The client can then use the JWT to authenticate itself with Document Engine, which will return only the data that the user is authorized to view.

A JWT typically grants access to a specific document and the [Instant layer](https://www.nutrient.io/api/reference/document-engine/upstream/#tag/Layers) combination. If you’re having difficulty generating valid JWTs, you can use the [Document Engine dashboard](https://www.nutrient.io/guides/document-engine/management/dashboard.md) to [validate](https://www.nutrient.io/guides/document-engine/viewer/client-authentication/validate-a-jwt.md) them.

Additionally, as seen in our [Catalog project example](https://github.com/PSPDFKit/react-native/blob/master/samples/Catalog/examples/InstantSynchronization.tsx), you’ll need to initialize the Nutrient Instant viewer with the license key or demo key to open a PDF document:

```js

Nutrient.setLicenseKey('Enter your license key here');
Nutrient.presentInstant
	//...document configuration
	();

```
---

## Related pages

- [Adding Instant comments to PDFs in React Native](/guides/react-native/instant-synchronization/comments.md)
- [Syncing PDF annotations in React Native](/guides/react-native/instant-synchronization/annotation-sync.md)
- [Create and manage PDF annotation layers in React Native](/guides/react-native/instant-synchronization/instant-layers.md)
- [Integrating real-time collaboration into your React Native application](/guides/react-native/instant-synchronization/get-started.md)
- [Instant sync and document state in React Native](/guides/react-native/instant-synchronization/document-state.md)
- [Nutrient Instant usage on React Native](/guides/react-native/instant-synchronization/usage.md)
- [PDF collaboration library for React Native](/guides/react-native/instant-synchronization.md)
- [Offline PDF annotations with sync on React Native](/guides/react-native/instant-synchronization/offline-support.md)