This quiet little TypeScript repo tackles a genuinely underserved corner of accessibility engineering: switch scanning. For readers unfamiliar with the term, switch scanning is an input method used by people with significant motor impairments who can't operate a mouse, keyboard, or touchscreen. Instead, a highlight cycles through on-screen options and the user activates a single physical switch (a button, a sip-and-puff device, a head-mounted contact) at the moment their target is highlighted. It's the backbone technology behind AAC (Augmentative and Alternative Communication) apps used by people with ALS, cerebral palsy, and spinal cord injuries.

What makes this repo intriguing even at zero stars is who shayc is — a longtime contributor in the open-source AAC space, previously behind CBoard, a browser-based communication board. A dedicated switch-scanning primitive extracted into its own TypeScript library suggests the beginnings of a reusable building block that other AAC and accessibility tool authors could drop into their own web apps.

The interesting design questions in a library like this are non-trivial:

• Scan patterns: linear, row-column, group-item, half-and-half — each trades speed for cognitive load
• Timing: auto-scan intervals, dwell times, debouncing accidental double-hits
• Input abstraction: mapping arbitrary key events, gamepad buttons, or Bluetooth switch interfaces to a single logical "select"
• Focus management: integrating cleanly with existing DOM focus and ARIA semantics rather than fighting them

Who benefits? Web developers building AAC apps, educational software for special-needs classrooms, or inclusive kiosk interfaces. Also anyone curious about how accessibility technology actually works under the hood — reading a focused library like this is a much faster education than wading through the W3C accessibility specs.