Google's Topics API provides the functionality to include interest-based user information in bid requests using something called topics when Media Owners are integrated with Index Exchange (Index) using Prebid.js 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 IDv=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.
The header metadata is transformed to the following OpenRTB fields:
| Topics header metadata | OpenRTB field |
|---|---|
The exchange-specific name for the data provider that observed the topic IDs. |
If Index observed the topic IDs, the |
The taxonomy version |
|
The model version mapping |
|
The topic ID |
|
For more information on how DSPs receive topics information, see How Index sends Privacy Sandbox topics in bid requests.
