Tech Stack

Tech Stack

MoodHaven Journal is a local-first desktop app built on Tauri v2 (Rust backend) with a React/TypeScript frontend. All user data lives on-device in an encrypted SQLite database.

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Core Stack

Layer	Technology	Notes
Desktop shell	Tauri 2 (Rust)	Native OS integration
Frontend	React 18 + TypeScript	Strict mode, no any
Styling	TailwindCSS 3	Custom colour tokens
Rich text	TipTap	ProseMirror-based
State	Zustand	4 stores
Database	SQLite via rusqlite (bundled)	Single file, no server
Encryption	AES-256-GCM + PBKDF2	WebCrypto API
Peer identity	Ed25519 (ed25519-dalek)	Device signing key
Peer discovery	mDNS/DNS-SD (mdns-sd)	LAN auto-discovery
2FA	totp-rs + native CTAP2/HID	TOTP + hardware keys
HTTP (Rust)	reqwest (json + stream features)	WebDAV sync, Oura API
Charts	Custom SVG	No charting library
Logging	tauri-plugin-log + src/lib/services/logger.ts	Rotating file (prod), stderr (dev)
Testing	Vitest + Testing Library	693 tests
Build	Vite 8 + Tauri CLI
Mobile	Kotlin + Wear OS Data Layer	MessageAPI + ChannelAPI

Browser / PWA Build

The browser build replaces Tauri IPC with IndexedDB via Vite module aliasing:

Module	Desktop	Browser
Data persistence	SQLite (rusqlite)	IndexedDB (src/lib/backend/browser.ts)
IPC layer	@tauri-apps/api/core invoke	src/lib/backend/browser-invoke.ts shim
Tauri-only plugins	Native	No-op stubs (src/lib/backend/browser-stubs.ts)
HTTP	@tauri-apps/plugin-http	window.fetch

State Management (Zustand Stores)

Store	What it holds
appStore	isInitialized, isUnlocked, theme, active view
settingsStore	All user preferences (AI, appearance, privacy, journal, health)
booksStore	books[], activeBookId
peerSyncStore	identity, nearbyPeers, trustedDevices, isDiscovering

Frontend Architecture

Component
    │
    ▼
  Hook  (state + side effects)
    │
    ▼
 Service  (IPC wrappers or pure functions, src/lib/)
    │
    ▼
 Tauri invoke → Rust command handler

Services are thin IPC wrappers or pure utilities — they hold no state. Components use hooks; hooks call services.

Tauri Command Layer

~109 Rust commands registered in src-tauri/src/lib.rs, split across ~21 modules in src-tauri/src/commands/. Each command is:

1. Defined in src-tauri/src/commands/<module>.rs
2. Declared in src-tauri/src/commands/mod.rs
3. Registered in src-tauri/src/lib.rs inside invoke_handler!(...)
4. Permitted in src-tauri/capabilities/default.json
5. Wrapped in src/lib/<service>.ts

Full command reference: docs/tauri-commands.md

STT (Speech-to-Text)

• Engine: whisper.cpp binary as Tauri sidecar
• Models: on-demand download from Hugging Face to app_data_dir/models/
• Audio: Web Audio API → 16 kHz mono WAV → sidecar → stdout text → insert at cursor → delete WAV
• All processing is local — no audio ever leaves the device

View Routing

Navigation is handled by a ViewType enum in appStore. No URL routing library.

ViewType: writing | timeline | onthisday | insights | calendar | settings

Full architecture: docs/architecture.md