Android XR SDK Developer Preview 4 Adds Unreal, Godot, and a Tool That Changes the Workflow

Google released Developer Preview 4 of the Android XR SDK this month, and this update matters more than the version number suggests. For the first time, Android XR officially supports Unreal Engine and Godot alongside Unity, and a new tool called the Android XR Engine Hub unifies the development workflow across all three engines. Combined with core libraries moving to beta and new interaction components for glasses, DP4 marks the point where Android XR stops being a Jetpack-only platform and becomes accessible to the broader game development community.

Unreal and Godot Change the Math

Prior to DP4, building for Android XR meant either using Jetpack XR with Kotlin in Android Studio or using Unity. That covered a meaningful portion of the developer ecosystem, but it excluded the large number of studios and indie developers who build in Unreal Engine or Godot. Unreal powers a significant share of VR titles on Steam and Quest, and Godot has been growing rapidly as an open-source alternative that appeals to smaller teams and solo developers.

Adding official support for both engines is Google acknowledging a practical reality: if you want developers to build for your platform, you meet them where they already work. Asking a studio with years of Unreal tooling and expertise to rewrite their pipeline in Unity or Kotlin is a nonstarter. Now they do not have to.

There is one important caveat. Game engine support currently applies to headsets and wired XR glasses like XREAL's Project Aura. Audio glasses and display glasses are still Jetpack XR SDK and Android Studio only. That makes sense given the different interaction models, but it means the full engine ecosystem is limited to immersive devices for now.

Engine Hub Is the Real Story

The Android XR Engine Hub might be the most quietly significant tool Google has shipped for XR developers this year. It runs on Windows and acts as a high-speed bridge between your Android XR device and whichever engine you prefer. The Hub streams device-created perception data (hand tracking, spatial mapping, eye tracking, controller input) from the headset or glasses directly into Unity, Unreal, or Godot in real time.

In practical terms, this means you can develop and test XR experiences in your engine of choice with live device data without building and deploying to the headset after every change. That tightens the iteration loop dramatically. Anyone who has done VR development knows that the build-deploy-test cycle is one of the biggest time sinks in the process. Engine Hub cuts that cycle down to near-instant previewing.

Core Libraries Approaching Beta

Google announced that XR Runtime, Jetpack SceneCore, and ARCore for Jetpack XR are all moving to beta status. This is significant for production-focused teams because beta signals API stability. In the developer preview phase, APIs can change between releases, which makes it risky to build shipping products against them. Beta means the interfaces are locked down enough that you can start building with confidence that your code will not break on the next update.

The SDK has also been modernized with a Kotlin-first architecture, removing legacy Guava and RxJava3 dependencies. For developers already working in modern Android development patterns, this simplifies the codebase. For teams coming from older Android projects, it means some migration work, but the result is a cleaner and more maintainable foundation.

Glasses Get Interactive Components

DP4 introduces new UI components specifically designed for glasses: Title Chips and Button Groups optimized for touchpad input. This is the kind of detail that signals Google is moving past the "make it work" phase and into the "make it work well" phase for glasses development. Building UI for a device with no hand controllers and limited input methods requires purpose-built components, and these are the first set designed specifically for the glasses touchpad interaction model.

The Catalyst Program

Alongside DP4, Google opened applications for the Android XR Developer Catalyst Program. The program targets developers planning to publish apps for Android XR in the next 6 to 12 months using Kotlin and Jetpack XR SDK, or Unity, Unreal, and Godot. Selected developers get early hardware access, direct engineering support from Google, and resources designed to accelerate their development timeline.

For studios considering whether to invest in Android XR development, the Catalyst Program is worth applying to regardless of how far along your project is. Early hardware access alone justifies the application, given that most developers are still working against emulators and spec sheets rather than physical devices.

What This Means for the Platform

Developer Preview 4 represents the moment Android XR became a three-engine platform with real tooling behind it. The combination of Unreal and Godot support, Engine Hub, beta-quality core libraries, and the Catalyst Program removes most of the practical objections developers had about building for Android XR. The remaining question is whether the hardware install base will justify the investment. With Samsung Galaxy XR already shipping, Project Aura coming this year, and audio glasses arriving this fall, Google is building toward that critical mass. DP4 ensures the developer tools are ready when the hardware arrives in volume.