# ⚙️ Functions & API

Plexus communicates primarily through WebSockets (Socket.io) for real-time interaction.

## 🔌 Socket Events

### 📥 Client to Server
- `join({ walletAddress, username })`: Register or login a user.
- `sendMessage({ channelId, walletAddress, content, txId })`: Send a message to a channel.
- `toggleReaction({ messageId, walletAddress, emoji })`: Toggle a reaction on a message.
- `updateUsername({ walletAddress, newUsername, txId })`: Change username (simulated cost).
- `getProfile(walletAddress)`: Fetch user profile and wall posts.
- `updateProfile({ walletAddress, bio, bannerColor })`: Update profile details.
- `createPost({ walletAddress, content })`: Post a message to the user's wall.

### 📤 Server to Client
- `userList(users)`: Broadcast the updated list of online/offline users.
- `newMessage(message)`: Broadcast a new message to all clients.
- `updateReactions({ messageId, reactions })`: Broadcast updated reactions for a message.
- `usernameUpdated({ username })`: Confirm a username change to the specific user.
- `profileData(data)`: Send requested profile data to a user.
- `profileUpdated(data)`: Confirm profile update.
- `postCreated(post)`: Confirm post creation.
- `error({ message })`: Send error messages to the client.

## 🌐 REST API
- `GET /api/channels`: List all available chat channels.
- `GET /api/messages/:channelId`: Fetch the last 100 messages and reactions for a channel.

## 🛠 Internal Logic
- **Username Authority**: The server validates and ensures unique usernames, appending suffixes if necessary.
- **Transaction Simulation**: The client simulates a 1.5s delay and a 5% failure rate for "blockchain" transactions.