What is tinytouch?

tinyTouch is a do it yourself project that lets you log in, run sudo commands, and authenticate on a Mac using a fingerprint sensor, wirelessly, instead of buying Apple's $149 Magic Keyboard with Touch ID. It is built around an ESP32 microcontroller connected to a fingerprint sensor, and it offers two different ways of working, which the project calls red pill and blue pill mode. In red pill mode, called HID mode, the device pretends to be a regular USB keyboard. After your fingerprint is matched, a small helper program on your Mac sends your real password to the device in encrypted form, and the device types it in for you, then immediately forgets it. This makes it work almost anywhere your password would normally work, including remote login sessions, but it does mean your actual password is briefly typed out by the device each time. In blue pill mode, called PIV mode, the device instead pretends to be a USB smart card, the kind macOS already knows how to use for secure login. Your fingerprint gates access to a private security key stored on the device, and macOS talks to it using its built in smart card system rather than typing your password at all. This is described as the more secure option, though it only works in places where macOS accepts smart cards, such as the lock screen and sudo prompts, not everywhere a password would work. The README is unusually direct about the security tradeoffs of building your own authentication hardware. It includes tables comparing attack scenarios for both modes, and openly states that anyone who leaves their computer physically accessible to people they do not fully trust, or who handles sensitive company or classified information, should stick with an official, more secure device instead. Setup involves flashing custom firmware onto the ESP32 board using either the Arduino IDE or the ESP-IDF toolchain, generating cryptographic keys with OpenSSL, running a Python helper script on macOS, and wiring up the physical hardware yourself. The README lists the exact commands for both modes but assumes comfort with command line tools, firmware flashing, and basic hardware wiring. It does not include a parts list beyond a partial hardware table, and it is written specifically for macOS users, not Windows or Linux.