Knowledge base

Introduction to Unified Auction

Getting started with Unified Auction

Welcome to the Unified Auction documentation hub. Here you’ll find information about the platform and integration documents that allow you to participate in Unity’s real-time bidding exchange. Unified Auction provides demand-side partners (DSPs) access to exclusive inventory, a comprehensive range of advertising formats, and 1.5 billion Unity users across 80,000+ apps globally.

Unified Auction allows DSPs and advertisers to bid on each ad impression. All Unified Auctions are first-price auctions, meaning all programmatic advertising buyers will have the opportunity to bid and pay the value they decide for an impression. Unity’s implementation is based off the OpenRTB 2.3 specification, and may require parameters that are optional for the Interactive Advertising Bureau (IAB). Please read the integration guidelines and contact Unity if you have any questions.


In order to participate in Unified Auction, please review the following criteria:

  • Support for OpenRTB 2.3+: Unity supports OpenRTB 2.3, and some components of OpenRTB 2.5. Partners should support similar specs as described here.
  • Implement nURL impression tracking: nURL is a field in the bid response’s bid object, or the win notice URL called by the real-time bidding (RTB) exchange. nURL is one of several unique bid response requirements necessary for Unity integration, which are identified in the attribute description columns.
  • Development resources: Partners implementing Unity’s version of OpenRTB should have sufficient development resources to complete the following:
    • A pre-Integration questionnaire that helps Unity understand how best to support your integration.
    • Creative asset validation.
    • Discrepancy check and ramp-up.

How it works

  1. Unity receives an ad request from a mobile device.
  2. Unity makes an HTTP POST request to all bidding partner endpoints (each bidder must respond within 200ms, total roundtrip). Unity passes this value through the bid request tmax field.
  3. Unified Auction runs a first-price auction based on valid bidder responses.
  4. Upon winning the auction, Unity retrieves the winning bid’s HTML and imptrackers to the client for pre-caching.
  5. When the user surfaces the ad, Unity pings the winning bidder’s nURL (required field) to notify the DSP of the impression.
  6. The creative renders to the end user, and Unity fires other event trackers along with the creative payload.

Documentation resources

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Last updated on 16th May 2022