Permissions-Policy: browsing-topics directive
Limited availability
This feature is not Baseline because it does not work in some of the most widely-used browsers.
Non-standard: This feature is not standardized. We do not recommend using non-standard features in production, as they have limited browser support, and may change or be removed. However, they can be a suitable alternative in specific cases where no standard option exists.
Deprecated: This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.
The HTTP Permissions-Policy header browsing-topics directive controls access to the Topics API.
Where a policy specifically disallows the use of the Topics API, any attempts to call the Document.browsingTopics() method or send a request with a Sec-Browsing-Topics header will fail with a NotAllowedError DOMException.
Syntax
Permissions-Policy: browsing-topics=<allowlist>;
<allowlist>-
A list of origins for which permission is granted to use the feature. See
Permissions-Policy> Syntax for more details.
Default policy
The default allowlist for browsing-topics is *.
Specifications
This feature is not part of an official standard, although it is specified in the Topics API Unofficial Proposal Draft.