Herdr and the Throughput Case for Parallel Coding Agents

Most agent tooling is still built around a single conversation: one agent, one task, one terminal, one stream to babysit. Fine for small tasks, bad for real engineering work. Herdr is interesting because it treats that as the default shape of the work. The simplest way to describe it is: Herdr is tmux for coding agents. More precisely, it is an agent multiplexer that runs inside your existing terminal. It gives each agent a real PTY, keeps processes alive where the work is happening, shows agent state, and exposes a CLI plus a local socket API. That distinction matters. Herdr is not another desktop agent app. It is a binary you run where the code and terminals live: a server, a Mac Mini, a VM, a dev machine under your desk. Close the laptop, detach, ssh back later, reattach, even from a phone. The work did not die because your terminal window did. The throughput problem Coding agents changed the cost of starting work. I can ask one agent to explore a bug, another to write a failing test, another to draft a migration plan. The bottleneck is supervision. The problem is that normal terminals do not understand supervision. tmux and Zellij give you persistence and panes, but they do not know whether an agent is blocked, working, done, idle, or just sitting there after printing a question three screens ago. Desktop apps often understand the agent state better, but then the workflow is stuck to the machine with the GUI. Worktree orchestrators can coordinate parallel tasks, but they usually want to own the workflow. Herdr sits in a useful middle: terminal model, plus agent awareness. The performance multiplier is not magic. It comes from four practical properties: Multiple agents run in real PTYs, each with its own shell, logs, prompts, and process state. Herdr rolls up semantic state, so you can see which agents are blocked, working, done, or idle. The server owns the panes, so sessions survive client detach, laptop sleep, and terminal death. The CLI and socket API let scr