Admin /help Command — Design#

Goal#

Add an admin-only /help slash command to the chat that shows available commands as a system notice. Build a command registry so /help auto-generates from registered commands.

Key Decisions#

• Admin-only dispatch: Only isOwner connections trigger command handling. Non-admin users typing /help or any /command have their message sent as regular chat text — no error, no hint that commands exist.
• Server-side registry: Commands are registered in a central registry. /help iterates the registry to build its output.
• System notice display: The help output renders as a styled system notice in the chat, visible only to the admin (not broadcast).
• New HELP server message type: Carries an array of { name, description } so the client can render it cleanly.

Architecture#

Command Registry (api/src/commands.ts)#

interface Command {
  name: string;
  description: string;
  handler: (ws: WebSocket, args: string, chatRoom: ChatRoom) => void;
}

• Exports a commands array and a dispatch(text, ws, chatRoom) function.
• dispatch is only called when isOwner is true.
• Built-in commands: /help, /unblock <ip>.

Dispatch Flow#

In handleChatMessage:

1. If info.isOwner and text starts with / → call dispatch(text, ws, chatRoom)
2. If dispatch returns true (command matched) → return early
3. Otherwise → treat as normal message

Server Message Type#

New HELP type added to SERVER_MESSAGE_TYPE and ServerMessage union:

interface ServerHelpMessage {
  type: "help";
  commands: Array<{ name: string; description: string }>;
}

Client Handling#

In chat-client.ts, handle help message type by calling appendNotice() with formatted command list.

Files Changed#

Example Output#

When admin types /help:

Available commands:
  /help — Show this help message
  /unblock <ip> — Unblock a user by IP address