XR Blocks

AI-native library for rapid AI + XR prototyping & innovation

Site — Manual — Templates — Demos — Gem — YouTube — arXiv — Blog

Description

XR Blocks is a lightweight, cross-platform library for rapidly prototyping advanced XR and AI experiences. Built upon three.js, it targets Chrome v136+ with WebXR support on Android XR (e.g., Galaxy XR, XREAL Aura) and also includes a powerful desktop simulator for development. The framework emphasizes a user-centric, developer-friendly SDK designed to simplify the creation of immersive applications with features like:

Hand Tracking & Gestures: Access advanced hand tracking, custom gestures

with TensorFlow Lite / PyTorch models, and interaction events.

Hand Gesture Recognition: Opt into pinch, open-palm, fist, thumbs-up, point,

and spread detection with options.enableGestures(), tune providers or thresholds, and subscribe to gesturestart/gestureupdate/gestureend events from the shared subsystem.

Head Gesture Recognition: Detect completed nod and shake motions with

options.enableHeadGestures() and subscribe through xb.input.headGestures on device or in the desktop simulator.

World Understanding: Present samples with depth sensing, geometry-aware

physics, planes, scene meshes, object recognition, human pose, face landmarks, and semantic segmentation in XR and the desktop simulator.

Unified Interaction: Use one target and capture pipeline for mouse, gaze,

hand rays, controllers, direct touch, spatial UI, and object manipulation.

Built-in Spatial UI: Compose world-space cards and view-space overlays from

flex-layout panels, text, images, icons, buttons, sliders, and themes.

Agent Context: Expose an agent-facing scene context with semantic trees,

visible-object state, and Set-of-Mark screenshots through xb.context.

AI Integration: Seamlessly connect to Gemini for multimodal

understanding and live conversational experiences.

Cross-Platform: Write once and deploy to both XR devices and desktop

Chrome browsers.

We welcome all contributors to foster an AI + XR community! Read our blog post and white paper for a visionary roadmap.

Usage

XR Blocks can be imported directly into a webpage using an importmap. This code creates a basic XR scene containing a cylinder. When you view the scene, you can pinch your fingers (in XR) or click (in the desktop simulator) to change the cylinder's color. Check out this live demo with simple code below:

<!DOCTYPE html>
<html lang="en">
  <head>
    <title>Basic Example | XR Blocks</title>
    <meta charset="utf-8" />
    <meta
      name="viewport"
      content="width=device-width, initial-scale=1.0, user-scalable=no"
    />
    <link
      type="text/css"
      rel="stylesheet"
      href="https://cdn.jsdelivr.net/gh/google/xrblocks@main/samples/main.css"
    />
    <script type="importmap">
      {
        "imports": {
          "three": "https://cdn.jsdelivr.net/npm/[email protected]/build/three.module.js",
          "three/addons/": "https://cdn.jsdelivr.net/npm/[email protected]/examples/jsm/",
          "xrblocks": "https://cdn.jsdelivr.net/gh/google/xrblocks@build/xrblocks.js",
          "xrblocks/addons/": "https://cdn.jsdelivr.net/gh/google/xrblocks@build/addons/"
        }
      }
    </script>
  </head>
  <body>
    <script type="module">
      import * as THREE from 'three';
      import * as xb from 'xrblocks';
/**
       * A basic example of XR Blocks to render a cylinder and pinch to change its color.
       */
      class MainScript extends xb.Script {
        init() {
          // Add a simple light to the scene.
          this.add(new THREE.HemisphereLight(0xffffff, 0x666666, 3));
// Create the 3D object.
          const geometry = new THREE.CylinderGeometry(0.2, 0.2, 0.4, 32);
          const material = new THREE.MeshPhongMaterial({
            color: 0xffffff,
            transparent: true,
            opacity: 0.8,
          });
          this.player = new THREE.Mesh(geometry, material);
// Position the object in front of the user.
          this.player.position.set(
            0,
            xb.user.height - 0.5,
            -xb.user.objectDistance
          );
          this.add(this.player);
        }
/**
         * Changes the color of the mesh on a pinch or click.
         */
        onSelectEnd(event) {
          this.player.material.color.set(Math.random() * 0xffffff);
        }
      }
// When the page content is loaded, add our script and initialize XR Blocks.
      document.addEventListener('DOMContentLoaded', function () {
        xb.add(new MainScript());
        xb.init(new xb.Options());
      });
    </script>
  </body>
</html>

Gem

For rapid prototyping, please refer to this blog and try out XR Blocks Gem on Android XR or desktop using Chrome.

A video demonstration of XR Blocks Gem can be found here.

Development Guide

Setup

# Clone the repository.
git clone --depth=1 [email protected]:google/xrblocks.git
cd xrblocks
Install dependencies and build the SDK.
npm ci

After setup, either serve the samples and demos or develop locally, as described below.

Serve samples and demos

Serve the repository to view samples and demos through http://localhost:8080/:

# Serve the repository on http://localhost:8080
npm run serve

Develop locally

For active SDK development, run watch mode and local serving together:

# Build the SDK in watch mode and serve the repository on http://localhost:8080
npm run dev

Linting and formatting

XR Blocks uses Oxlint for linting and Prettier for formatting. Run the following commands to check your code before submitting a pull request:

npm run lint # Oxlint check
npm run format # Prettier format

If you are using VS Code, install the Oxc extension and the Prettier extension, then set Prettier as your default formatter.

Devtools

For local before/after Chrome measurements, see the standalone profiler. It records interleaved samples and raw traces and generates a static HTML report, with optional WebGL depth-call counters.

For additional agent-first development tools including UI visualizers, 3d model visualizers, CLI based embodied XR Blocks runners, and automatic agent controls, see XR Blocks Devtools.

Notice

This is not an officially supported Google product, but will be actively maintained by the XR Labs team and external collaborators. This project is not eligible for the Google Open Source Software Vulnerability Rewards Program.

User Data & Permissions

When using specific features in this SDK (e.g., WebXR, hand tracking, camera), users will be prompted with permission requests and the application may not function as expected with denied permissions.

XR Blocks is an open source software development kit that does not handle data by itself; however, the use of other APIs may collect user data and require user permissions:

When using WebXR and LiteRT APIs (e.g., depth sensing, gesture recognition), all data is stored and processed locally with on-device models.

When using AI features (e.g., Gemini Live, Gemini Flash), the data will be sent to Gemini servers and please follow Gemini's Privacy & Terms.

Keep Your API Key Secure

This SDK does not require any API keys for non-AI samples. In specific AI use cases, this SDK provides an interface to use cloud-hosted Gemini services with XR experiences, requiring an API key from AI Studio. Please follow this doc for best practices to keep your API key secure.

Treat your Gemini API key like a password. If compromised, others can use your project's quota, incur charges (if billing is enabled), and access your private data, such as files.

Critical Security Rules

Never commit API keys to source control. Do not check your API key into version control systems like Git.

Never expose API keys on the client-side. Do not use your API key directly in web or mobile apps in production. Keys in client-side code (including our JavaScript/TypeScript libraries and REST calls) can be extracted.

Uninstallation

To remove XR Blocks from your code, simply remove the lines from your Chat with me

google/xrblocks: XR Blocks is a lightweight WebXR + AI library for rapidly prototyping advanced AI + XR experiences.