@CIMB4 @mcc @astrid there's a huge community around building kit keyboards where you buy the main pcb, switches, etc separately. These most often use a firmware called QMK, but ZMK is similar and allows using Bluetooth. You can use zmk on any keyboard that uses a separate microcontroller by replacing it with a Bluetooth capable microcontroller board. There are a bunch of websites that sell keyboard kits of this type in various configurations.