Document how to evaluate the packages that will enable revalidateTag behavior with the CDN and internal caches

[stevector]

We have a "Pantheon Advanced Page Cache" plugin for WordPress and a module for Drupal that enable metadata to pass from the origin CMS to the CDN as surrogate keys. When CRUD operations fire within the CDN, these packages can then reach out from origin infrastructure to the CDN to purge the appropriate caches.

We expect we will create the same capacity for Next.js to clear CDN caches itself when revalidateTag is fired.

While there will be internal differences between how this functionality works for the CDN and for the internal cache, I hope that developers implementing this functionality don't need to think much about it. Perhaps this can/should be rolled into a wider Deployment Adapter implementation. Related:

• Document how to evaluate the package that will enable ISR behavior through a cache handler #9727
• Document Build Adapters API usage (or lack thereof) #9732

We will also need to consider how these packages intersect with the behavior of

• The cache clear button in the dashboard.
• terminus env:clear-cache
  I think my preference, at least at first, is to require an opting in to platform-level cache clearing invoking this package/application level cache.

[stevector]

#9894 is updating documentation for the existence of https://github.com/pantheon-systems/nextjs-cache-handler

Once that PR is merged I think we can close this issue. Any subsequent specific questions/discussions about the behavior of that cache handler should happen in the issue queue of that repo.

[stevector]

https://docs.pantheon.io/release-notes/2026/02/nextjs-cache-handler