Architecture Overview

This document provides a high-level view of the system architecture.

System Context Diagram

High-Level Architecture

Technology Stack

Layer	Technology	Purpose
Frontend	React 19	UI Components
	Tauri 2	Desktop runtime (Rust)
	WatermelonDB	Offline-first local database
	Lexical.js	Rich text editor
	Material UI	Component library
Backend	Cloudflare Workers	Serverless runtime
	Cloudflare D1	SQLite database
	Hono	REST API framework
	tRPC	Type-safe RPC
Sync	Custom Protocol	Pull/Push sync
	Yjs	CRDT for text collaboration
Communication	HTTP	REST & tRPC queries
	WebSocket	Real-time tRPC

Data Flow

Key Concepts

Offline-First

The app works completely offline. All data is stored locally in WatermelonDB (SQLite). When online, changes sync bidirectionally with the server.

Type Safety

tRPC provides end-to-end type safety. Types defined in the Worker are automatically available in the Tauri app via workspace linking.

CRDT Collaboration

Rich text fields use Yjs (CRDT) for conflict-free merging. Multiple users can edit the same document, and changes are merged on the server.

Next Steps

• Frontend Stack - React, Tauri, WatermelonDB, Lexical
• Backend Stack - Workers, D1, Hono, tRPC
• Communication - REST vs tRPC vs WebSocket
• Sync Protocol - Offline-first sync architecture
• CRDT Collaboration - Yjs and conflict resolution