# Advertisement tester
Schedule ad breaks in a stream and inspect the resulting ad events and companion ads.
Tip: open your browser's developer console and use the `player` and `THEOplayer` variables to interact with this demo.
### Ad configuration
Ad templatesVAST pre-roll (vast-preroll)Video URLhttps\://cdn.theoplayer.com/video/big\_buck\_bunny/big\_buck\_bunny\_metadata.m3u8Ad URLhttps\://cdn.theoplayer.com/demos/preroll.xmlIntegrationTHEOplayer (CSAI) (csai)PositionPre-roll (start)
Load sourceReset to template
Generated code
```js
player.source = {
"sources": {
"src": "https://cdn.theoplayer.com/video/big_buck_bunny/big_buck_bunny_metadata.m3u8",
"type": "application/x-mpegurl"
},
"poster": "https://cdn.theoplayer.com/video/big_buck_bunny/poster.jpg",
"metadata": {
"title": "Big Buck Bunny"
},
"ads": [
{
"sources": "https://cdn.theoplayer.com/demos/preroll.xml",
"integration": "csai",
"timeOffset": "start"
}
]
};
// Schedule an ad break at any time:
player.ads.schedule({
"sources": "https://cdn.theoplayer.com/demos/preroll.xml",
"integration": "csai"
});
```
### Events
Clear
No events reported yet.
THEOplayer supports client-side ad insertion (CSAI) of VAST and VMAP ads through the `csai` integration, and ads served through Google's IMA SDK with the `google-ima` integration. VPAID and non-linear overlay ads require `google-ima`. Ad breaks are scheduled with the `ads` array in the source, or at any time with `player.ads.schedule()`. A `timeOffset` of `'start'` schedules a pre-roll, `'end'` a post-roll, and a timestamp or percentage a mid-roll; VMAP ads carry their own offsets and ignore `timeOffset`.
```js
player.source = {
sources: { src: 'https://example.com/video.m3u8' },
ads: [
{
sources: 'https://example.com/vast.xml',
integration: 'csai',
timeOffset: 'start',
},
],
};
// Schedule an ad break while the content is already playing:
player.ads.schedule({
sources: 'https://example.com/vast.xml',
integration: 'csai',
});
```
See [Set up VAST and VMAP](https://optiview.dolby.com/docs/theoplayer/how-to-guides/web/ads/set-up-vast-and-vmap.md), [Google IMA](https://optiview.dolby.com/docs/theoplayer/how-to-guides/web/ads/google-ima.md) and [Subscribe to ad events](https://optiview.dolby.com/docs/theoplayer/how-to-guides/web/ads/subscribe-to-ad-events.md).
Code
demo.html
```html
Advertisement tester
```