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Auction Details


Last updated on November 15, 2017

Below is an overview of auction details for OpenRTB server-to-server (S2S) supply integrations.

General OpenRTB Auction Process

  1. The publisher has an impression available and solicits a bid from OpenX via an OpenRTB bid request.

  2. OpenX aggregates bids from many demand sources and conducts a second-price auction.

  3. OpenX responds via an OpenRTB bid response with the bid price and the creative markup with an impression beacon appended.

  4. The publisher runs their auction and serves the OpenX creative if it wins. The publisher should also substitute the ${AUCTION_PRICE} macro with the winning price.


    The ${AUCTION_PRICE} macro expands to the clearing price using the same currency and units (CPM) as the bid.

  5. When the creative is rendered, the OpenX impression beacon is called and OpenX is notified of the win and auction price.

  6. The publisher sends reporting data to OpenX.

OpenRTB-integrated publishers can conduct either a first-price or a second-price auction. The diagrams below illustrate the differences between these auctions for integrated publishers.

Publisher First-price and Second-price Auctions

For a publisher first-price auction, all of the steps outlined above apply, except for step 5.

Auction detailsFirst-price auctionsSecond-price auctions
Process diagram
Step 5 differencesThe OpenX bid price should match the publisher auction price.The publisher auction price is expected to be less than the OpenX bid price.
Access to OpenX UI reportingYesNo
Reporting data availabilitySome reporting data is available in the OpenX UI.No reporting data is available in the OpenX UI.
Need to send metrics?YesYes