Herdr Adds Agent-State Awareness to Terminal Multiplexing

For developers already juggling Claude Code in one pane, Codex in another, and a third agent waiting on review, Herdr is a purpose-built answer to a problem that tmux was never designed to solve. It is an open-source terminal multiplexer with built-in awareness of AI agent states, written in Rust and distributed as a single binary with no external dependencies.

The core addition over a plain terminal multiplexer is a sidebar that tracks whether each running agent is blocked, working, done, or idle, displayed with color-coded indicators. Detection is automatic, driven by process names and terminal output analysis, and requires zero configuration for the 15+ agents the project supports by default, including Claude Code, GitHub Copilot CLI, Devin CLI, and Codex. Workspaces roll up to show the most urgent agent state at a glance, so you can tell which session needs your attention without switching to each pane manually.

The architecture follows a server-and-client model over a Unix socket, meaning sessions persist when you detach the client and agents keep running. The Unix socket API also allows agents to integrate more directly rather than relying purely on output scraping. The project describes its own positioning as "persistence and agent awareness in one tool that stays out of your way."

Licensing is dual-track: AGPL-3.0-or-later for open source use, with commercial licenses available for organizations that cannot comply with the copyleft terms. The AGPL constraint is worth flagging for enterprise teams, since it requires distributing source code of any modified version. Windows support is listed as a preview beta and not production-ready.

What the repository does not fully explain is how the blocked state is determined, whether parsed from specific output strings or inferred from process behavior, which matters for reliability across agents that format output differently. That said, 8.1k GitHub stars and 65+ releases suggest meaningful developer uptake, and the direction the tool points -- agent-aware persistence as a first-class terminal primitive -- is one worth watching.