Browser Client <--WebSocket--> Relay (Node.js) <--TCP--> Backend Minecraft Server (optional) Thus, a "plugin" can exist at the relay layer. // eaglercraft-plugin-example.js class EaglerPlugin onChatMessage(player, message) if (message.startsWith("!ping")) player.send("/tellraw @p \"text\":\"Pong!\""); return false; // cancel original message return true;