---
title: "Polygon layer (polygon helper) | JavaScript maps SDK"
description: "Add minimal polygon layer using MapTiler polygon helper."
---
# Polygon layer (polygon helper)
This example shows the process of incorporating a layer of polygons onto the map by utilizing the polygon layer helper and its default settings. Download the [Swiss sample data](../../assets/switzerland.geojson).
In this particular case, the color is assigned at random from a predetermined list of colors. This is the default behavior taken when a specific color is not designated.
### NPM module setup
```bash
npm install --save @maptiler/sdk
```
#### main.js
```js
import { Map, MapStyle, config, helpers } from '@maptiler/sdk';
import '@maptiler/sdk/dist/maptiler-sdk.css';
config.apiKey = 'YOUR_MAPTILER_API_KEY_HERE';
const map = new Map({
container: 'map',
zoom: 6.62,
center: [8.224, 46.823],
style: MapStyle.STREETS.LIGHT
});
map.on('load', async function () {
await helpers.addPolygon(map, {
data: 'YOUR_MAPTILER_DATASET_ID_HERE',
fillOpacity: 0.5,
});
});
```
#### index.html
```html
Polygon layer (polygon helper) | NPM example
```
#### style.css
```css
body {margin: 0; padding: 0;}
#map {position: absolute; top: 0; bottom: 0; width: 100%;}
```
### Basic JavaScript setup
```html
Polygon helper
```
## Related examples
### [Polygon fill pattern (polygon helper)](https://docs.maptiler.com/sdk-js/examples/helper-polygon-pattern/)
Examples
Add fill pattern to polygon layer using helper.
### [Polygon color ramp symbol (polygon helper)](https://docs.maptiler.com/sdk-js/examples/helper-polygon-ramped-style/)
Examples
Style polygon fill color based on zoom level.
### [GeoJSON polygon layer](https://docs.maptiler.com/sdk-js/examples/geojson-polygon/)
Tutorials
Add GeoJSON polygon overlay to your web map application.
### [Show polygon information on click](https://docs.maptiler.com/sdk-js/examples/polygon-popup-on-click/)
Examples
Display a popup when a user clicks a polygon.