I have no idea what ACP offers that are superior to a tmux session. With tmux, you can attach to it at any time, send keys at any time, and capture pane without bothering any running process inside.
And you don't have to get anyone's permission to use tmux.
> And you don't have to get anyone's permission to use tmux.
I'm not so sure about that. I have my own local multi agent orchestration setup with tmux and native claude code, codex, and gemini. They can talk between each other using tmux.
I'm not sure precisely when does a wrapper around Claude Code become a "third party harness". If OpenCode is a third party harness, why is tmux not?