plexus/docs/architecture.md

Architecture Overview

Plexus is designed as a real-time, decentralized-first chat application.

🏗 System Components

1. Frontend (Client)

• Built with Vue 3 and Vite.
• Uses Pinia for state management (messages, users, channels).
• Communicates with the backend via Socket.IO for real-time updates.
• Simulates Solana transactions for messages, reactions, and username changes.

2. Backend (Server)

• Built with Node.js and Express.
• Uses Socket.IO to handle real-time communication.
• DuckDB is used as the primary data store for:
  • User profiles (wallet addresses, unique usernames).
  • Message history.
  • Reactions.

3. Database Schema

• users: wallet_address (PK), username (UNIQUE), last_seen.
• messages: id (PK), channel_id, wallet_address, content, timestamp, tx_id.
• reactions: message_id, wallet_address, emoji.

🔄 Data Flow

1. User Joins: Client emits join with wallet address and requested username. Server verifies/generates unique username and updates users table.
2. Sending Message: Client simulates transaction, then emits sendMessage with txId. Server saves message to DuckDB and broadcasts newMessage to all clients.
3. Reactions: Client emits toggleReaction. Server updates reactions table and broadcasts updateReactions.

🛡 Security

• Currently uses a simple wallet-based identification.
• Future versions will implement full message signing and verification.