CesiumJS Viewer Setup

---
name: cesiumjs-viewer-setup
description: "CesiumJS viewer setup - Viewer, CesiumWidget, widgets, Ion token, Scene configuration, SceneMode, factory helpers, geocoders, platform services. Use when initializing a CesiumJS application, configuring viewer widgets, setting Ion access tokens, creating default terrain or imagery, or bootstrapping a 3D globe."
---

# CesiumJS Viewer & Scene Setup

Reference for bootstrapping CesiumJS applications: Viewer, CesiumWidget, Ion/GoogleMaps/ITwinPlatform configuration, widgets, factory helpers, geocoder services, viewer mixins, Credits, and related enums.

## Quick Start

```js
import { Ion, Viewer, Terrain } from "cesium";
import "cesium/Build/Cesium/Widgets/widgets.css";

// Always set your Ion token before any other Cesium calls
Ion.defaultAccessToken = "YOUR_CESIUM_ION_ACCESS_TOKEN";

const viewer = new Viewer("cesiumContainer", {
  terrain: Terrain.fromWorldTerrain(),
});
```

Required HTML: `<div id="cesiumContainer" style="width:100%;height:100vh"></div>`