An Accounter is responsible for somehow charging a client for a successful request or to deny the request if the client has insufficient funds.
When a request has been processed, and if the worker marked the request as successfully fulfilled, the configured Accounter (if any) is called. The Accounter implementation could potentially query an external database and make a purchase for the service.
The Accounter to use is configured using the ACCOUNTER worker property. By default no Accounter is used.
See also the section about all available Accounters.