The concrete problem
Running two or three coding-agent sessions is easy. Knowing when their work is safe to combine is not.
One session changes an API while another writes regression tests against the old shape. A third investigates a production failure and quietly edits the same configuration file. Git worktrees prevent immediate filesystem collisions, but they do not explain task dependencies, transfer assumptions, or warn that two agents are solving incompatible versions of the problem.
The developer becomes a human message bus: checking terminals, copying commit IDs, repeating context, and deciding which session should wait. The more capable each agent becomes, the less useful a wall of terminal panes is as a coordination interface.
The current signal
