Two-band architecture from docs/research/stt.md: renderer captures mic
audio in an AudioWorklet (linear16 16kHz mono, ~128ms frames, per-quantum
RMS for the meter) and streams it directly to Deepgram over WebSocket —
audio never loops through our server. The real key stays server-side;
/api/stt/token mints a short-lived grant token (TTL 300s) per run.
Patterns ported from the owner's pi dictate extension (tuned in real
use): generation counter guarding every async handler, the
latest-RMS-never-resets meter (-50..-10dB window, 60ms tick), mic-first
stop + CloseStream + 3s safety net, endpointing=300 with the
utterance_end_ms=1000 backstop.
UI (owner placement): mic button in the stats bar's middle slot on all
three surfaces (home graph-view, chat, draft); while recording the meter
unfurls to fill the row's free width with the interim ghost at its
flank. Esc ends dictation from the composer. Token mint comes before
getUserMedia so a keyless app fails fast without a TCC prompt; one
automatic reconnect on abnormal socket close, errors surface inline.
Live-smoked the full error path in the dev shell (bar renders on all
three pages, 403 grant failure shows inline, mic untouched). The full
audio path needs a Deepgram key with Member permission to mint tokens.
- Palette per the owner's hexes: background #141414, raised #1C1C1C,
edges #434343, ink tokens, destructs unchanged; :root and .dark carry
identical values (the app is always dark).
- Type ladder declared once (11px base, each size carries its own
line-height); radii ladder 4/8/12/16; spacing rhythm = Tailwind's 4px
scale. All documented in the globals.css header.
- Fonts: JetBrains Mono (chrome) + Source Sans 3 (prose) via
next/font/google in app/layout.tsx; CMU Serif bold bundled locally
(public/fonts/cmunbx.ttf) behind the lh-cmu @font-face.
- Prose/emphasis tokens: --lh-ink-strong (rust bold), --lh-ink-italic
(blue italic), .lh-prose wrapper — ready for the future settings UI.
- l.h-ink-strong/italic defaults sampled from the reference mockup.
amosblomqvist