OpenRTB 2.3 Ad Server API

Document created by catherine.racette on Dec 13, 2017Last modified by catherine.racette on Feb 1, 2018
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Real-time bidding (RTB), also referred to as OpenRTB, is the programmatic means of enabling bidding of individual ad impressions through real-time auctions. Inventory is purchased on an open exchange, allowing many buyers to bid on inventory from multiple publishers in an auction. This can be a highly effective way to get access to large audiences through open exchange programmatic buys.


PubMatic supports Ad Serving integration using OpenRTB 2.3, as well as a proprietary API. This documentation covers the OpenRTB Ad Serving integration. The latest OpenRTB 2.3 specifications are available at   


OpenRTB 2.3 Ad Server API for Publishers

OpenRTB Bid Request Objects and Parameters 

OpenRTB Bid Response Objects and Parameters 

OpenRTB Ad Server API Cookie Sync 



Buyer/DSP Reference: OpenRTB 2.3 for Buyers/DSPs