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Full-StackAI/ML

Sotto.

Offline desktop voice dictation — Rust/Tauri with Parakeet ASR (ONNX, Vulkan GPU), llama.cpp AI polish, and Harper grammar engine.

Sotto

A desktop voice-dictation app that runs entirely offline — hold a hotkey, speak, and Sotto transcribes, polishes, and pastes clean text into any application. No cloud, no subscription, no data leaving your machine.

How it works

Sotto chains three stages in a single pipeline:

  1. Capture — global push-to-talk hotkey (Right Ctrl, rebindable) records audio via cpal, with a cancel/retry escape hatch.
  2. Transcribe — NVIDIA Parakeet v3 int8 model running through ONNX Runtime with Vulkan GPU acceleration (70x faster than CPU). A secondary whisper.cpp engine (Whisper large-v3-turbo, also Vulkan) is wired up for planned multilingual/Arabic support.
  3. Polish — two tiers: short phrases get instant rule-based cleanup via Harper grammar engine; longer dictations route to Qwen 2.5 1.5B (Q4_K_M) running locally through a llama.cpp sidecar with full GPU offload.

The polished text is injected directly into the focused application via Windows keystroke simulation.

Architecture

Single Rust crate, ~11,500 lines of code across 16 backend modules and a vanilla HTML/CSS/JS frontend. Key modules: asr.rs (transcription), llm.rs (sidecar management), polish.rs (two-tier routing), hotkey.rs (global capture), inject.rs (clipboard + keystroke paste), stats.rs (usage analytics).

Models (~2.1 GB) download on first launch from GitHub Releases and are stored in a configurable directory.

Features

  • Insights dashboard — words dictated, WPM average, per-app breakdown, streak calendar
  • Dictation history — re-copy or re-polish any past take
  • Overlay pill — transparent always-on-top indicator, color-coded by state (lilac = listening, amber = transcribing, gold = polishing, blush = error)
  • Custom dictionary & snippets — expansion shortcuts for repeated phrases
  • “Marshmallow” design language — cream/lilac palette, Newsreader + Hanken Grotesk typography, light/dark/system themes
  • Auto-updater — minisign-signed delta updates (~4 MB) via GitHub Releases
  • Launch at login with minimized start and single-instance guard

v0.3.3 · 30 commits · NSIS installer for Windows x64