Google's Topics API provides the functionality to include interest-based user information in bid requests using something called topics when publishers are integrated with Index Exchange (Index) using Prebid.js An open-source library for publishers to implement header bidding on their websites and manage multiple header bidding partners. version 8.9.0 or later. These topics will supplement other contextual signals, such as first-party-data, and can be combined to help find an appropriate advertisement for your site’s visitors without the use of cookies in Chrome. The topics are selected from an advertising taxonomy based on the IAB Audience Taxonomy.
For more information about how the Topics API works and how Google proposes to preserve consumer privacy, see the Index Explains video explaining what is the Topics API.
Before you begin: In your Google Ad Manager configuration, make sure that you have enabled the Chrome Topics data setting. For more information about the configuration, see Google’s documentation on Topics API and Ad Manager.
Index receives topic information through the Sec-Browsing-Topics header in your incoming request and then transforms it so the information can be sent to DSPs.
For example, if the incoming Sec-Browsing-Topics contains the following information:
Sec-Browsing-Topics: (10);v=chrome.1:1:1, (12);v=chrome.1:2:2, ();p=P0000000000For (10);v=chrome.1:1:1
-
(10)is the topic ID -
v=chrome.1:1:1is the version, where:-
chrome.1is the configuration and follows the format of "<browser vendor identifier>.<an integer version>". -
:1is the taxonomy version used to compose the list of topic identifiers. For this example, version 1.
-
:1is the model used for topic classification, which gets mapped to an ID when passing the value to DSPs in bid requests. In this example, version 1 is mapped to 600 in the IAB Tech Lab in Enumeration of Taxonomies.
-
For (12);v=chrome.1:2:2
-
(
12)is the topic ID
-
v=chrome.1:2:2is the version, where:-
chrome.1is the configuration and follows the format of "<browser vendor identifier>.<an integer version>".
-
:2is the taxonomy version used to compose the list of topic identifiers. For this example, version 2.
-
:2is the model used for topic classification, which gets mapped to an ID when passing the value to DSPs in bid requests. In this example, version 2 is mapped to 601 in the IAB Tech Lab in Enumeration of Taxonomies.
-
The p=P0000000000 is additional padding used to make the header length consistent and isn't relevant information for the bid request An OpenRTB request that is sent from a supply-side platform (SSP) or ad exchange to the DSP requesting a bid response for potential impressions. A bid request contains information about the impression that allows the DSP to decide whether to bid on the impression..
The header metadata is transformed to the following OpenRTB An open industry standard for communication between buyers and sellers of online advertising in real-time bidding auctions. It's published by the IAB. fields:
| Topics header metadata | OpenRTB field |
|---|---|
| The exchange-specific name for the data provider that observed the topic IDs. | user.data.name
If Index observed the topic IDs, the name will always be topics.indexexchange.com.
|
| The taxonomy version | user.data.ext.segclass
|
| The model version mapping | user.data.ext.segtax
|
| The topic ID | user.data.segment.id
|
For more information on how DSPs receive topics information, see How Index sends Privacy Sandbox topics in bid requests.
