The Payment API provides us with functions to help process payments and deliver "goods" when payment is successful. However it lacks logging of payment actions/events.

If something goes wrong, then its difficult to check where things went wrong.
For example: A user says they have paid successfully but cannot access the course or resource. Currently no logs are recorded in Moodle to indicate where the payment process failed.

A payment gateway plugin could implement its own logging but it would be nicer if the Payment API logged important events within the payment process lifecycle for consistency.

Some of these events could be:

• Payment transaction started
• Payment transaction completed
• Payment transaction successful
• Payment transaction failed
• Payment transaction cancelled