Each event handler returns a corresponding response header. A response header is only returned when logging information is available for the event. The log header name starts with X-Akamai-EdgeWorker:

X-Akamai-EdgeWorker-onClientRequest-Log
X-Akamai-EdgeWorker-onOriginRequest-Log
X-Akamai-EdgeWorker-onClientResponse-Log
X-Akamai-EdgeWorker-onOriginResponse-Log
X-Akamai-EdgeWorker-responseProvider-Log

JavaScript Logging fields

EdgeWorkers JavaScript logging returns logs in the following format <debug-level>:<file>:<line> <message>.


JavaScript Logging fields	Details	Description
`<debug-level>`:`<file>`:`<line>`:`<message>`	`<debug-level>`	Currently the level is always "D" for debug.
	`<file>`	The URL encoded file name is only included if it is different from the previous log line.
	`<line>`	The line number where the log was executed.
	`<message>`	The URL encoded message. Includes values for any data included in the message. A vertical bar (\|) separates multiple messages. All text in the string is ASCII. Invalid characters and delimiters are percent encoded. A dollar sign appends text truncated by the byte limit.