As someone without PCB design experience but with dreams of physical things that could be made with PCBs this sounds amazing. What software are you using for the PCB design? Or just entirely letting Fable do whatever and checking the work with the browser page you mention?
The designs are in Kicad format, and the Kicad APIs are useful for Claude to work with. I would say that right now this involves a lot of knowledge about PCB design to do well, or for more detailed designs. However you might research how to design board for fabrication at JLCPCB and try something simple. Eg make a board with only LEDs in some pretty pattern and make it so you solder a raspberry pi Pico 2 to the board to drive it. Then you don’t have to worry about microcontroller work, just getting the LEDs placed. That is a little easier to get right. Just check the orientation of the LED footprint in the data sheet and make sure the four pins on the LED footprint match - and that there is a silkscreen dot on pin 1 of the LED. You can feed an agent this comment and it can check, though it’s good to check with your own eyes. You might ask it to screenshot the data sheet and the board footprint and display them side by side on the project web page for your review.
Put the LEDs in a cool pattern, slap a Pico on there, have your LLM program it, then dangle it off your backpack with a USB battery pack. Probably adding a motion sensor is easy enough.
Ask the LLM to make sure the board follows JLCPCB’s design rules, lists the LCSC part number for each part, verifies the parts are in stock, double checks every footprint, and makes sure the board passes DRC. Make sure it creates a schematic that is linked to the board design, and that the schematic is properly arranged in to logical blocks with clear connections the way a person would make a schematic - not a big array of parts with global labels for everything. Once it’s done, ask it to clean up the schematic and make it better. Repeat for the board layout. Ask it to review and look for issues multiple times. It will find them. Finally, take some time to doodle your own silkscreen art on there. Have fun! Note the Pico 2 is USB micro. For USB C, sparkfun or waveshare sell similar boards.
Also you can ask it to teach you! Ask a million questions and have it give you multimedia explainers.
I have both Altium and Kicad experience. Can you explain further how you are setting up the AI to interface with KiCad? Is your AI having keyboard/mouse access or are you doing it only through API? Not familiar with Claude interface.