Wireless ap client list from within pfsense?

[Zamboni111]

is it possible to monitor and manage wireless clients from within pfsense using an external wireless AP?

[almabes]

Monitor and manage in what fashion?
You can use bandwidthd to monitor bandwidth utilization by IP.
You can keep an eye on your DHCP leases, too from Status–DHCP Leases.

[Derelict]

Other than DHCP leases, etc, you are looking for functionality typically found in a wireless controller.