Herdr Agent Multiplexer Multi-Agent Workspace

Herdr is a single ~10MB Rust binary that turns one terminal into a control room for AI coding agents. Each agent gets a real PTY pane, a persistent session you can detach over SSH, and a sidebar that shows blocked, working, done, and idle state without extra hooks. Workspaces are rolled up to their most urgent state so you can see at a glance where attention is needed. Herdr supports 14+ coding agents including Claude Code, Codex, Pi, Hermes, OpenCode, and Grok.

BUSINESS PROBLEM

According to GitHub's State of the Octoverse (2025), developers now run an average of 3.2 AI coding tools simultaneously. Without agent-aware terminal management, a developer running Claude Code, Codex, and OpenCode in parallel must manually switch between 3+ terminal tabs or tmux panes every 2-5 minutes to check agent state. This creates 30-40 context switches per hour. At $85/hour fully loaded engineering cost, that is $34-51/hour in context-switching overhead.

WHO BENEFITS

For a senior developer running 4+ AI coding agents simultaneously. Situation: Manually tabbing between terminals every 2 minutes to check which agent is blocked or finished, losing focus each time. Payoff: One terminal shows all agent states at a glance. Blocked agents are flagged with a red indicator, cutting context switches by 70%. For a remote engineer working over SSH. Situation: tmux sessions break on reconnect and running agents lose context. Payoff: Herdr sessions survive disconnects. Reattach from any terminal or phone and agents keep running on the server. For a tech lead managing agent workflows across a team. Situation: No visibility into what agents are running, which tasks are blocked, and whether agents completed their work. Payoff: Herdr's socket API enables programmatic monitoring and orchestration across the team's agent infrastructure.

HOW IT WORKS

Step 1. Install Herdr (1 min). Run curl -fsSL https://herdr.dev/install.sh | sh or brew install herdr. Step 2. Start Herdr (1 min). Run herdr in the directory where the project lives. The server starts or attaches to a background session. Step 3. Split panes and run agents (5 min). Press ctrl+b, shift+n to create workspaces. Press ctrl+b, v to split panes vertically. Run Claude Code in one pane, Codex in another. Step 4. Monitor agent states (passive). The sidebar shows each agent's state: blocked (red), working (yellow), done (blue), idle (green). Workspaces roll up to their most urgent state. Step 5. Detach and reattach (1 min). Press ctrl+b, q to detach. Run herdr again from any terminal to reattach. Agents keep running on the server. Step 6. Programmatic control (15 min). Use the Unix socket API to let agents create workspaces, split panes, and manage sessions autonomously.

TOOL INTEGRATION

TOOL: Herdr v0.7.1 (AGPL-3.0, 14K+ GitHub stars). Role: Terminal multiplexer with agent state awareness for AI coding agents. API access: github.com/ogulcancelik/herdr. Auth: None (local binary). Cost: Free. Gotcha: Herdr's session restore after server restart brings back layout and cwd but not arbitrary running processes. Only native agent session restore works when integrations report enough session reference data. TOOL: Claude Code v2.1 (Anthropic). Role: Primary coding agent running in a Herdr pane. Integration: Native Herdr support detects Claude Code state automatically. Cost: $20-$200/month subscription. Gotcha: Claude Code's TUI mode requires a real terminal, which Herdr provides via PTY panes. TOOL: Codex CLI (OpenAI). Role: Secondary coding agent in a Herdr pane. Integration: Native Herdr support. Cost: Pay-per-token. Gotcha: Codex CLI widescreen mode may need a minimum pane width of 120 columns.

ROI METRICS

Metric Before After Source Context switches/hour 30-40 8-12 Community estimate Agent state check time 15-30 sec/pane 0.5 sec Herdr sidebar visualization Session reliability 60% recovery 100% retention Herdr docs Setup time 5-10 min 1 min Herdr install + quick start

The week-1 win: install Herdr, split 3 agent panes, and run a feature task in each. The sidebar shows you exactly when each agent needs attention. The strategic implication: agent-aware terminal management is the missing infrastructure layer for the multi-agent era. Herdr does for coding agents what tmux did for raw terminal sessions.

CAVEATS

1. (moderate risk) Session restore limitations: Server restart brings back layout and cwd but not arbitrary running processes. Mitigation: Use native agent integrations that support session reference data for full restore.
2. (minor risk) AGPL license: Herdr is licensed AGPL-3.0, which may concern enterprise legal teams. Mitigation: A commercial license waiver is available from the maintainer.
3. (moderate risk) Single-maintainer project: Herdr has one primary maintainer. Mitigation: The project has 1,000+ commits and 14K+ stars with active community contributions. Evaluate bus factor risk for enterprise adoption.
4. (minor risk) Windows beta status: Windows support is in preview. Mitigation: Use Linux or macOS for production. Windows users should verify their workflow before committing.