[Unit]
Description=Weechat IRC Client (in tmux)
After=network.target

[Service]
User=pew
Type=oneshot
RemainAfterExit=yes
ExecStart=/usr/bin/tmux new-session -d -s irc /usr/bin/weechat
ExecStop=/usr/bin/tmux kill-session -t irc

[Install]
WantedBy=multi-user.target