---
title: "Instant usage on Android | Nutrient SDK"
canonical_url: "https://www.nutrient.io/guides/android/pspdfkit-instant/usage/"
md_url: "https://www.nutrient.io/guides/android/pspdfkit-instant/usage.md"
last_updated: "2026-05-21T20:35:00.913Z"
description: "This guide will give you an overview of the Instant API and how to use it for displaying documents from the server. for Nutrient Android SDK."
---

# Instant usage on Android

This guide will give you an overview of the Instant API and how to use it for displaying documents from the server.

## API Overview

The entry class into Instant is [`InstantClient`](https://www.nutrient.io/api/android/nutrient/com.pspdfkit.instant.client/-instant-client/index.html). This represents a connection to Document Engine. An app typically creates one [`InstantClient`](https://www.nutrient.io/api/android/nutrient/com.pspdfkit.instant.client/-instant-client/index.html), although it could create several to connect to multiple Document Engine instances.

Instant manages downloading and storing PDF files when your app requests this. Each PDF file managed by Instant is identified by its `documentId` and can have one or more named [layers](https://www.nutrient.io/guides/android/pspdfkit-instant/instant-layers.md). Each layer represents a separate set of annotations displayed on top of the base document and is identified by its name.

In your app, each Instant layer is represented by an `InstantDocumentDescriptor` instance that can be created by calling [`getInstantDocumentDescriptorForJwt()`](https://www.nutrient.io/api/android/nutrient/com.pspdfkit.instant.client/-instant-client/get-instant-document-descriptor-for-jwt.html) on an [`InstantClient`](https://www.nutrient.io/api/android/nutrient/com.pspdfkit.instant.client/-instant-client/index.html). For each document layer, your app must obtain a JSON Web Token (JWT) from your server.

A document descriptor may be used to request downloading the associated PDF file and all annotations in the layer. Once that has finished, an [`InstantPdfDocument`](https://www.nutrient.io/api/android/nutrient/com.pspdfkit.instant.document/-instant-pdf-document/index.html) may be created. Set this document on an [`InstantPdfFragment`](https://www.nutrient.io/api/android/nutrient/com.pspdfkit.instant.ui/-instant-pdf-fragment/index.html) or [`InstantPdfActivity`](https://www.nutrient.io/api/android/nutrient/com.pspdfkit.instant.ui/-instant-pdf-activity/index.html) and then show it to the user. Changes to annotations will be synchronized for all users viewing the same document.

[`InstantPdfFragment`](https://www.nutrient.io/api/android/nutrient/com.pspdfkit.instant.ui/-instant-pdf-fragment/index.html) is a subclass of [`PdfFragment`](https://www.nutrient.io/api/android/nutrient/com.pspdfkit.ui/-pdf-fragment/index.html), just as [`InstantPdfActivity`](https://www.nutrient.io/api/android/nutrient/com.pspdfkit.instant.ui/-instant-pdf-activity/index.html) is a subclass of [`PdfActivity`](https://www.nutrient.io/api/android/nutrient/com.pspdfkit.ui/-pdf-activity/index.html), and both can be used to show only [`InstantPdfDocument`](https://www.nutrient.io/api/android/nutrient/com.pspdfkit.instant.document/-instant-pdf-document/index.html). Trying to display a [`PdfDocument`](https://www.nutrient.io/api/android/nutrient/com.pspdfkit.document/-pdf-document/index.html) instance will result in an exception being thrown. Conversely, showing a [`PdfDocument`](https://www.nutrient.io/api/android/nutrient/com.pspdfkit.document/-pdf-document/index.html) created by Instant in any activity or fragment not subclassing [`InstantPdfActivity`](https://www.nutrient.io/api/android/nutrient/com.pspdfkit.instant.ui/-instant-pdf-activity/index.html) or [`InstantPdfFragment`](https://www.nutrient.io/api/android/nutrient/com.pspdfkit.instant.ui/-instant-pdf-fragment/index.html), respectively, is not supported.
---

## Related pages

- [Adding Instant comments to PDFs on Android](/guides/android/comments/introduction-to-instant-comments.md)
- [Efficient PDF annotation syncing on Android](/guides/android/pspdfkit-instant/syncing.md)
- [Authenticate your Android app with JWT](/guides/android/instant-synchronization/authentication.md)
- [Instant sync and document state on Android](/guides/android/pspdfkit-instant/instant-document-state.md)
- [Frequently asked questions](/guides/android/instant-synchronization/faq.md)
- [PDF collaboration library for Android](/guides/android/instant-synchronization.md)
- [Integrating real-time collaboration into your Android application](/guides/android/pspdfkit-instant/getting-started.md)
- [Create and manage PDF annotation layers on Android](/guides/android/pspdfkit-instant/instant-layers.md)
- [Effortless offline PDF annotation and sync](/guides/android/pspdfkit-instant/offline-support.md)