Do I need the bassinet for my baby with the smart lux?

No as the seat reclines into a lie flat mode. The smart lux bassinet utilises the frame of your smart lux seat. The bassinet is offered as an optional accessory - it offers extra depth, padded sides and a firm side enabling it to be used off the frame as well. You can also use this without a harness if this preferred - the harness needs to be used with the seat.