I think the op meant on the protocol level, not client. You can literally do `cat mycommands.txt > /dev/tcp/...`. IRC is pretty simple, I remember using telnet just for fun to connect (also the PING message replies are annoying to type yourself) and at one time, (ab)used an FXPable FTP server data port trickery in ASCII mode to send a message to a channel.

Due to its simplicity I could see its application as a falback for global communication downtime/outages (as we had with FB/Insta recently).