Glance-Type — origin note¶

Written: 2026-06-14 · Owner: Mohsen Seyedkazemi Ardebili Shipped as: design/v2-cognitive-layer/03-glance-type.md · ADR-v2-010 · ADR-011 (offline-by-construction posture) Tier: design/ — public. Historical origin note; the implementation docs above are the current source of truth.

The idea¶

The pitch was to close the loop between attention and action: look at a pane, dictate, and the text lands there — no click, no Alt-Tab, no reaching for the mouse to re-aim the caret. The honest boundary was stated up front, before any code: commodity webcam gaze estimation is region-grade, not pixel-grade, so the buildable version was look-to-pane, never look-to-letter.

The survey that grounded it found the perception half solved — real-time face/iris tracking at ~90 FPS for a few percent of CPU, and gaze-direction models reporting under 4° angular error on standard benchmarks — but the screen-mapping half bounded: the best published webcam-to-screen accuracy sits in the tens of millimetres even with a still head, and degrades further under head motion. A line of text is a few millimetres tall; tens of millimetres of error rules out caret precision on a webcam, full stop. The decision gate that followed was explicitly conditional: build the coarse, pane-level, always-falls-back-to-the-focused-window version now, and treat caret precision as blocked on a state-of-the-art jump that hadn't happened yet.

What shipped¶

Look-to-pane targeting shipped as src/yazses/gaze/ — a MediaPipe-based default backend, an affine calibration map, and a confidence-gated routing policy that falls back to the focused window whenever gaze confidence is low, exactly as the original prototype plan specified. It ships off by default, needs a one-time calibration pass and (for window focusing) X11, and frames are processed in-RAM during a hold and never stored — the privacy posture the original card treated as non-negotiable. Caret-level precision was never attempted; the scope stayed at the pane/window grain the evidence supported.