Built-in system variables

This table lists all the built-in system variables available to you. For any of these items that are optional, such as filename extensions, the inserted variable may yield a blank string. Note that the AKA prefix for the first variable listed varies from all others.

NameDescription
AKA_PM_CACHEABLE_OBJECTEither true if the requested object is cacheable, or false if not.
AK_BASE_URLThe incoming request URL, from the first to the last slash inclusive, and excluding the scheme and host. See the example. See the example.
AK_CLIENT_IPClient IP address as seen by the Akamai server, possibly overridden by X-Forwarded-For or Akamai-Client-IP request headers.
AK_CLIENT_REAL_IPThe client IP address as seen by the Akamai server, ignoring any request headers.
AK_CLIENT_RTTMilliseconds elapsed for the TCP round-trip (RTT) between client and edge server.
AK_CLIENT_TRANSFER_TIMEMilliseconds elapsed to transfer content from edge to client. This value is only available after the client response completes. Applies only to custom log fields.
AK_CLIENT_TURNAROUND_TIMEThe time in milliseconds between receiving the end of the request headers and writing the first byte of the reply to the client socket. This includes the time it takes for the edge servers to fetch the object from another server or to perform validation of the object's freshness if the object was in cache. In both of these cases there is a forward request corresponding to the client request. Note that this variable only applies to custom log fields and can be successfully used only when enclosed in an matchAdvanced.
AK_CONNECTED_CLIENT_IPThe IP on the TCP socket, either client or a redirecting ghost.
AK_CPCODEThe CP code assigned to the request.
AK_CURRENT_TIMEThe epoch time when edge metadata is applied to the request. If necessary, use the setVariable behavior to convert epoch time values to other time formats.
AK_DOMAINThe hostname without the initial subdomain, such as example.com when requesting www.example.com. See the example.
AK_EXTENSIONThe filename extension of the incoming request. See the example.
AK_EDGEWORKERS_FAILUREPopulated when an EdgeWorkers error occurs.
AK_EDGEWORKERS_RP_STATUSThe execution status of the EdgeWorkers event using the responseProvider event handler.
AK_EDGEWORKERS_STATUSThe execution status of the EdgeWorkers event using the onOriginRequest/Response and onClientRequest/Response event handlers.
AK_FILENAMEThe complete filename of the incoming request. See the example.
AK_FIREWALL_ALERTED_RULESWith webApplicationFirewall enabled, a colon-separated list of IDs for firewall rules that triggered an alert for the current request.
AK_FIREWALL_DENY_RULEIDWith webApplicationFirewall enabled, the ID for a firewall rule set to deny the request when the rule triggers.
AK_FIREWALL_DETECTED_RULESWith webApplicationFirewall enabled, a colon-separated list of IDs for all firewall rules that apply to the request.
AK_FIREWALL_MITIGATED_RULESA colon-separated list of IDs for firewall rules that were mitigated for the current request.
AK_FIREWALL_TRIGGERED_RULESA colon-separated list of IDs for firewall rules that were triggered for the current request.
AK_GHOST_IPThe IP address on which end client requests are received, and ultimately resolve for the end user.
AK_GHOST_SERVICE_IPThe edge server IP address used to forward a request, also commonly known as the machine IP. This is the IP address the origin server sees as the client IP when it receives a request from the edge.
AK_HOST_CNAME_CHAINA space-delimited list of the CNAME chain provided by DNS lookup on the incoming Host header.
AK_HOSTThe incoming request's hostname. See the example.
AK_MAPRULEThe maprule for the incoming request, such as a123.g.akamai.net.
AK_METHODThe request method, such as GET, PUT, POST, or HEAD.
AK_ORIGINAL_URLThe same as AK_URL, but before processing to remove any repeated forward slashes in the path. Just exactly as the edge servers received it.
AK_ORIGIN_DNS_NAMEThe hostname the Akamai server resolved to go forward to the origin.
AK_PATHThe original URL path as seen by the Akamai Edge server. See the example.
AK_PROTOCOL_NEGOTIATIONThe protocol negotiated with the client when NPN or ALPN is in use. For HTTP2, values are h2-14 or h2. For HTTP3, values are h3-29 or h3. For SPDY, values are spdy/3.1, spdy/3 or spdy/2. For HTTP, contact your ​Akamai​ representative for help configuring values http/1.1 or http/1.0.
AK_QUERYThe URL's entire query string. See the example.
AK_REFERENCE_IDThe global identifier for the request across the Akamai platform.
AK_REQUEST_IDUnique identifier for each request on the edge server, the same as reported in logs.
AK_SCHEMEThe request scheme, either http or https. See the example.
AK_SLOTThe incoming request's slot number.
AK_TLS_CIPHER_NAMEFor HTTPS and SPDY requests, specifies the name of the cipher used for the SSL connection, otherwise NO-CIPHER for HTTP requests.
AK_TLS_ENCRYPTION_BITSBits of encryption used for the request.
AK_TLS_PREFERRED_CIPHERSThe value of the request's security:essl.slot-assignment.preferred-ciphers tag.
AK_TLS_SNI_NAMEThe SNI name submitted by the client.
AK_TLS_VERSIONThe TLS version used for the connection.
AK_URLThe incoming request URL, including the query string, and excluding the scheme and host. See the example.

Example of the URL-related variables