Closing a ticket automatically, after being solved by an agent or higher support tier personnel is a common request across virtually all Service Desk tools.
We strongly advise not to close tickets this way, however, here is how to achieve it with GLPI if you have a reason:
First, you need to have Automatic actions running, either using GLPI pseudo-cron or Linux / Windows cronjob.
Automatic action taking care of closing of tickets is „closeticket“ and needs to be in Scheduled status. Run frequency does not matter much when closing tickets, let it be as is, let’s say 2 hours and set Run period corresponding with your customers‘ or users‘ work hours since you’d prefer not to spam them with closing notifications outside of business hours.
Once we have correctly set up the Automatic action, navigate to your Entity options, Assistance tab and set Automatic closing of solved tickets after to 0 days.
To test this change, we can put a ticket in a Solved state and run the Automatic action manually. The ticket should be automatically closed after that. Please note you may need to alter notifications settings in order to send either Solved or Closed notification since they’ve become redundant.
That being said, we advise against this scenario. According to most, if not all IT service management frameworks, following a process like Incident Management or Request Fulfilment, there is always the last process step before closing a ticket, which is verifying of the user satisfaction.
Consider adding a new duty to your Service Desk Operator role, which would be reaching the user by phone, e-mail, or even in person to verify if the outcome of the ticket meets user’s expectations. And only after this confirmation, close the ticket by hand or just let it be closed automatically after a couple of days.