Your applicationId.
Optional
clientThe id of the client that initiated this request. This is only relevant in cases that the request was initiated by a client such as when securing an api call or a DB operation. This id will not be available for triggers, schedulers, webhooks and other functions that are not directly initiated by a user action.
Optional
headersThe headers of the request. Headers are in lower-case.
Optional
sourceThe IP address of the client that initiated this request.