Essentially what I'm trying to do is create a GUI that can send vanilla commands and display the results of the commands.   Here's what I've tried: Minecraft.getMinecraft().thePlayer.sendChatMessage(command) doesn't work because that sends the results of the commands to the GuiChat , not my custom GuiScreen . ClientCommandHandler.instance.executeCommand(commandSender, command) doesn't work because CommandHandler 's commandMap is empty, implying normal commands aren'