The design is based on the excellent Dactyl keyboard, generated with https://ryanis.cool/cosmos/ and it runs the excellent qmk firmware. It is handwired: 
and I have also made a palm support using inkscape and openscad 
All printed on a reprap prusa i3 derivative.
This helps me use my computer with less pain, so I want to call out all the wonderful projects and people who contribute to them which made it possible.
Total cost? $60 aud, amortised filament ~15 bucks worth maybe? and a lot of my time haha.
The hand wiring is really easy. It just takes a long time.
Basically it’s just a grid, and a diode per switch. Then you wire each column and each row into a microcontroller.
You can do it!