apple-app-site-association CDN

I just watched the "What's new in Universal Links" video and was curious about the Apple CDN specifically for apple-app-site-association files.

Where can I find more information about it, and start debugging it?

I specifically have questions about how to ensure the latest version of the apple-app-site-association file is fetched after updating it. I assume it's with cache-related header, like Age, Etag, etc.


Hi poutine! The CDN's cache is invalidated periodically, however at this time we are not publishing details. If you run into issues or have a specific scenario that you believe we need to support, please let us know via the Feedback Assistant. We'd love to hear from you.
Is there any update on this issue because this is still happening and unfortunately I was not able to find any solution out there, if there is any.

I have also submitted a feedback on 'Feedback Assistant' but no response yet.
It would be great to have some docs (any docs!) here.

  • What's the invalidation policy on the CDN cache?

  • What's the iOS device refresh policy? It seems like it's only on app update or install, but if there's periodic refresh, we'd like to know about it.

  • Detailed docs on the association file format. The WWDC video that mentions substitution variables doesn't really cut it.

  • What's the user agent value for the CDN when it fetches the file? Can we make variants based on iOS version or app version?

Based on the lack of response to my prior bugs, I will not be filing an issue with Feedback Assistant.

Our team is going to be updating the links we use for deeplinking soon, and it’s very important to not break deeplinking in production. We are doing QA before release. But since iOS 14, when we start QA we have issues with deeplinking for around three days before it starts working. 

Will Apple please provide us with some information about how often the CDN's cache is invalidated and what happens if the request for apple-app-site-association files fails? Without this information, we don’t know how the system works, if the issues we have in testing will impact production, and if our users will experience deeplinking not working. Deeplinking is a very important feature for our app, and our users’ experience should not suffer because Apple won’t share documentation with developers.

I see in that the user-agent string for the Apple App Site Association CDN bot is AASA-Bot/1.0.0, but there is still a lot of missing information about how the Apple App Site Association CDN works.

Could we add the “Universal Links” tag to this post (and maybe remove the “Linker” tag if necessary)?

Thank you!