Topics API Taxonomy version through fetch call

[relevance-api-topics]

Hi Topics API experts,

When taxonomy has a new version, the topic ids also would change if we understand it correctly, through fetch calls, looks like there is no easy way to access taxonomy version, how do we ensure backward compatibility or do we miss anything? Thanks!

[jkarlin]

The taxonomy version is part of the request header sent with a topics-enabled fetch request.

e.g., if the header is "(1 2);v=chrome.1:2:5, ();p=P000000000" then the version is chrome.1:1:2. Where chrome.1 is the configuration version, the 2 is the taxonomy version, and 5 is the model version.

It's not particularly easy to find, but it's described in the spec.

@xyaoinum can you update the explainer to clarify the breakdown of the component string?

[xyaoinum]

The version breakdown is now clarified in the explainer. (commit: https://github.com/patcg-individual-drafts/topics/commit/3cb31f5b6d507044d5e4e83a0407cf18270a14f7)

[relevance-api-topics]

thanks @jkarlin, @xyaoinum thanks for the info! quick follow-up question is 'chrome.1' as the configuration, it's chrome.1 meaning there is other choices other than chrome? thanks.

[xyaoinum]

@relevance-api-topics Currently, in Chrome, the configuration version always starts with chrome..

[Dixie5644]

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[Dixie5644]

6.

[Dixie5644]

• 6.