Protected Audience multi-seller auction demo

[kevinkiklee]

Description

This PR implements Protected Audience multi-seller auction. In a multi-seller auction, the winning ad can be a header bidding auction winner, an ad server auction winner, or a Protected Audience auction winner.

• For header bidding and ad server auctions, the DSPs will provide a random bid value between 0 and 50.
• For a Protected Audience auction, the DSPs will provide a random bid value between 0 and 100 in order to increase the likelihood of seeing a PA ad for demo purposes.
• In this demo, the ad server acts as the top-level seller, but does not have to be. Any SSP can be the top-level seller.

To see the demo:

• Visit https://privacy-sandbox-demos-shop.dev/items/1f45e?auctionType=multi to add the IGs
• Visit https://privacy-sandbox-demos-news.dev/?auctionType=multi to see the ads

(This code has not been merged nor deployed to prod yet)

Related PR: #240

Instructions

To run the multi-seller demo:

1. Visit the shop item page and add the query param ?auctionType=multi (https://privacy-sandbox-demos-shop.dev/items/1f45e?auctionType=multi)
2. Visit the publisher page and add the query param ?auctionType=multi
   (https://privacy-sandbox-demos-news.dev/?auctionType=multi)

Services and libraries added

• DSP-A / DSP-B / SSP-A / SSP-B have been added to act as participants in a multi-seller auction
• Ad Server service has been added to host the ad server client-side library and to provide ad server auction result
• Header bidding library has been added to fetch header bids from the participants. The lib is hosted on the publisher site.

Multi-slot capability

The ability to render multiple ads have been implemented via the ad server library. The publisher can define an adUnit that describes the ad. And each ad unit participates in one sequential auction.

Example usage:

const sellers = ['<%= SSP_A_HOST %>', '<%= SSP_B_HOST %>']
const imageIframeAdUnit = {
  divId: 'image-ad--iframe',
  type: 'image',
  size: [300, 250],
  isFencedFrame: false
}

const imageFencedFrameAdUnit = {
  divId: 'image-ad--fenced-frame',
  type: 'image',
  size: [300, 250],
  isFencedFrame: true
}

const videoIframeAdUnit = {
  divId: 'video-ad--iframe',
  type: 'video',
  size: [300, 250],
  isFencedFrame: false
}

startSequentialAuction(imageIframeAdUnit, sellers)
startSequentialAuction(imageFencedFrameAdUnit, sellers)
startSequentialAuction(videoIframeAdUnit, sellers)

Sequence

1. The user is added to interest groups by DSP-A and DSP-B on the shop item page
2. The user visits the publisher page
3. The publisher page starts the Header Bidding auction
4. The header bidding library receives the bids and component auction configs from SSP-A and SSP-B (the perBuyerSignals is gathered from DSP-A and DSP-B by both SSPs)
5. The publisher page starts the Ad Server auction
6. The ad server library receives the bids from SSP-A and SSP-B who gathered the bids from DSP-A and DSP-B
7. The publisher page starts the Protected Audience auction
8. The ad server library renders the winning ad

Affected services

• Home
• News
• Shop
• Travel
• DSP
• DSP-A
• DSP-B
• SSP
• SSP-A
• SSP-B
• ALL
• Ad-server

[Svenmay]

I have added some comments where I believe we could improve the readability of the code. But I haven't found any major issues that should block submission.

[Seburan]

please review my comments and let me know if that works for you