The key is born on the chip.

During setup the chip inside the bronze frame creates the private key. The steps happen on the slab. You watch the screen for the words you must write down, and you use the buttons when the device asks for a PIN. You do not paste a secret in from somewhere else, and you do not email one to yourself so you will “have it later.”

The computer’s job, later, is narrower. A program on that computer can assemble a request: which keys to use, what the destination is, what the amount is. It sends that request down the USB-C cable. The chip checks it, the glass shows it, and only the middle button can approve a signature. The private key stays behind the charcoal face for that whole path.

People lose keys when a copy escapes. A screenshot, a notes app, a support chat, a shared drive. Quantumicy is built so the ordinary path does not create those copies. The chip can sign. It is not built to export the key into the program that asked for the signature.

The recovery phrase is the deliberate exception, and it is handled once, on the glass, onto paper. That paper is not a second device. It is the backup of the secret the chip created. How to treat it is the subject of the note on the eighteen words.

If you want the physical layout of the chip’s neighbors — the screen, the buttons, the port — start with the hardware page.