Tauri 2.0 rebuild — 5MB app, pure Rust, no Electron #4002

Originally written by @ccantynz-alt on GitHub.
Imported from https://github.com/ccantynz-alt/48co.v1/pull/35

Tauri 2.0 Rebuild — Complete App From Scratch

What changed

Scrapped Electron entirely. Rebuilt as a Tauri 2.0 app with a pure Rust backend.

Why

• 5MB app vs 150MB Electron — no antivirus warnings, instant install
• Pure Rust audio capture, keyboard simulation, HTTP — no Node.js, no nut-tree, no native compilation issues
• One codebase for Windows + Mac (iOS + Android via Tauri plugins in Phase 4-5)
• Modern stack: Rust + React + Vite + Tailwind

Architecture

tauri-app/
  src-tauri/src/
    lib.rs        — App setup, system tray, global shortcut, commands
    audio.rs      — Mic capture (cpal), WAV encoding (hound)
    transcribe.rs — Whisper API with proper errors
    keyboard.rs   — System-wide typing (enigo)
    grammar.rs    — Post-processing + Claude AI rewrite
  src/
    App.jsx       — Settings UI (clean, light theme)

Phases

1. NOW: Windows + Mac desktop app with Whisper API
2. Next: whisper.cpp for on-device transcription (no API)
3. Next: Phi-3 Mini for on-device grammar (no API)
4. Later: iOS keyboard (Swift Tauri plugin)
5. Later: Android keyboard (Kotlin Tauri plugin)

https://claude.ai/code/session_01PBeNmPHrD2W6A2YKZRC7V3