Herdr: a terminal multiplexer for AI coding agents

My notes

Summary

Herdr is a terminal multiplexer built specifically for running multiple AI coding agents at once. It keeps each agent alive in its own real PTY on a persistent server, so sessions survive the terminal (or laptop) closing, and you can reattach from any machine, including a phone over SSH. Unlike desktop agent-manager apps, it stays inside your existing terminal and can leave the local machine entirely.

Key Insight

• Fills a real gap: tmux/Zellij give persistent sessions but are agent-blind; desktop agent apps understand agents but are chained to one GUI machine. Herdr is the intersection - a terminal multiplexer that is agent-aware.
• Semantic agent state at a glance: shows blocked / working / done / idle across every pane, so you can babysit a whole fleet without reading each buffer.
• Persistence is the killer feature: agents run on a server (a Mac Mini, sandbox VM, any SSH box) and keep running after you detach. The value “shows up the first time the herd keeps running after your terminal disappears.”
• Machine-agnostic attach: herdr --remote workbox installs on the host, bridges local clipboard (including image paste), and preserves your keybindings - a local client onto a remote session.
• Agents can orchestrate it themselves: a CLI + JSON socket API exposes workspaces, panes, output, and waits (e.g. herdr wait agent-status 1-1 --status done), so an agent can spawn/split panes and block on sibling agents programmatically.
• Deliberately lightweight: a single binary, no Electron, no account, no telemetry, no hosted control plane. Stable on Linux/macOS, Windows in preview beta.
• Keeps your existing terminal (Ghostty, Kitty, iTerm, Alacritty) plus fonts and keybinds - not a rebuilt chat UI.