Modify Client Response Header

Category: Headers

Purpose: Each response contains a set of response headersThis type of header describes the HTTP response provided by a server. Among their many uses, certain response headers may be used to define the cache policy for the requested content. that describe it. This feature can either:

• Append or overwrite the value assigned to a response header. If the specified request header does not exist, then this feature will add it to the response.
• Delete a response header from the response.

By default, response header values are defined by an origin server and by our edge servers.

One of the following actions can be performed on a response header:

Option	Description	Example
Overwrite	The response header value will be set to the specified value.	Response header value (Origin/Edge Server): Value1 Response header value (Rules Engine): Value2 New response header value: Value2
Append	The specified value will be added to the end of the existing response header value.	Response header value (Origin/Edge Server): Value1 Response header value (Rules Engine): Value2 New response header value: Value1Value2
Delete	Excludes a header from the response.	Response header value (Origin/Edge Server): Value1 Response header value (Rules Engine): Result: The specified response header will be excluded from the response provided by our edge servers to the requester.

Key information:

• Make sure that the value specified in the Name option is an exact match for the desired response header.

• Case is not taken into account for the purpose of identifying a header.

  For example, any of the following variations of the Cache-Control header name can be used to identify it:

  • cache-control
  • CACHE-CONTROL
  • cachE-Control
• Deleting a header will prevent it from being forwarded to the requester.
• Use HTTP variables within the Value option to dynamically construct the response header value.

• The following headers are reserved and cannot be modified by this feature:

  • accept-ranges
  • age
  • connection
  • content-encoding
  • content-length
  • content-range
  • date
  • server
  • trailer
  • transfer-encoding
  • upgrade
  • vary
  • via
  • warning
  • All header names that start with "x-ec" are reserved.