Woodpecker and Robin are supporting 8 GPIOs.
Those GPIOs are provided by the Embedded Controller. On Robin the GPIOs are available on the FFC connector while Woodpecker is providing the GPIOs on the Com Express connector.
If more GPIOs are needed, the Oak USB 24 Digital I/Os at 3.3V or 5V Logic Level can be used. Other USB-, PCIe- to-GPIO may be used as well.