There is a note in my runbooks that says the Enter key works. That is almost the whole note. Press Enter and the prompt submits. I wrote it in bold, with sources and a date, because one of my AI agents once fixed the Enter key. The fix was the bug.
The Fix Was the Bug
I run a fleet of Claude Code agents in tmux panes. An orchestrator script types a prompt into a pane and presses Enter for it. One day an agent decided the submissions were not going through, and it knew the fix: send a backslash before the Enter. That sounds plausible if you have ever fought a terminal. It is also exactly backwards. In Claude Code, backslash plus Enter inserts a newline. It is the multiline key. So the fix turned every prompt into a draft that quietly grew longer and never sent. The panes looked busy. Nothing was happening.
The submissions had been fine all along. The agent just had not waited for the reply.
What broke: An agent changed Enter to backslash-Enter to repair prompt submission. Backslash-Enter creates a newline, so the repair silently stopped every prompt from sending. The system it fixed had never been broken.
