Cache Tag Visibility

Cache Tag Visibility determines how Cache Tags are returned on a request for the property.

Features and options

Cache Tags are returned based on these options:

  • Do not return Cache Tags. Cache Tags included in the Edge-Cache-Tag header aren’t returned. Instead, the response matches the default one on ​Akamai​'s edge servers.

  • Return Cache Tags only when Pragma header is sent. Cache Tags included in the Edge-Cache-Tag header are returned only when you pass in a Pragma: akamai-x-get-cache-tags header as part of the request.

  • Return Cache Tags with every request. Cache Tags included in the Edge-Cache-Tag header are returned in all responses.

👍

Cache tags can include back-end information, or at least allow a malicious user to decipher back-end information from them. To help with this, you can set this to Return Cache Tags only when Pragma header is sent. This way, you can limit the return of cache tags by requiring the Pragma: akamai-x-get-cache-tags header in a request.

How to confirm the Cache-Tag value

You can view the Edge-Cache-Tag value currently used for a particular object or URL by sending the ​Akamai​ Pragma header, Pragma: akamai-x-get-cache-tags in your request.

Here's an example request using curl with the Pragma header added:

curl -k -S -s -D - -o /dev/null -H "Pragma: akamai-x-get-cache-tags" https://www.example.com/test/

And, here's an example response with the Edge-Cache-Tag value that's being used:

HTTP/2 200 OK
Content-Type: text/html
Content-Length: 584010
Date: Mon, 9 May 2021 18:55:46 GMT
Last-Modified: Mon, 9 May 2021 17:28:16 GMT
Accept-Ranges: bytes
Server: AmazonS3
Edge-Cache-Tag: test-platform

📘

If you're stripping the ​Akamai​ Pragma headers in your ​Akamai​ configuration as a security measure, you'll also need to send the Request headersuch as the Cookiethat bypasses this behavior.