title: Are there Akamai debug headers that can be used to determine if and when a cache-tag was purged/invalidated/deleted?
body: <p>Currently our organization is using the Akamai Fast Purge v3 API to invalidate cache records by cache tag. The problem I'm running into is that some of our lower environments are configured with a TTL of 0 seconds, apparently to facilitate business user testing.</p>
  <p>As a result, I'm finding it strangely difficult to manually test the new purge system we have in place because Akamai isn't actually caching anything. We're working with the business to set this to closer match production environments, but in the meantime I'm wondering if there are any debug headers that can be used to figure out if and when an invalidation / deletion occurred.</p>
  <p>I have of course googled and <a href="https://community.akamai.com/customers/s/article/Using-Akamai-Pragma-headers-to-investigate-or-troubleshoot-Akamai-content-delivery?language=en_US" rel="nofollow noreferrer">found this somewhat useful if not incomplete and IMO strangely half-baked</a> article from Akamai themselves that discuss debug cache headers and their meaning, but it seems very incomplete.</p>
  <p>As far as I can tell, <code>X-Cache</code> is my best option from this article and as mentioned because of the 0 second TTL I will always get a <code>MISS</code>.</p>
  <p>Are there any additional debug headers that could be useful in determining if my purge logic is effective, despite the 0 second TTL?</p>