herdr is a Rust binary that serves as a background server for running coding agents, praised for its pane state model and agent-driven coordination, but criticized for missing cost accounting and unattended run logging.
I read herdr at a single pinned commit from 27 August, against a list of eighteen workspace patterns I keep for agent setups, and re-checked the cost side today at v0.9.1. For anyone who hasn't used it, herdr is a Rust binary that runs as a background server and owns the terminals your coding agents run in. Claude Code, Codex and the rest run unmodified inside it, and it's at about 41k stars. Two things stood out as good and two as missing. The pane state model is the right primitive. Every pane is working, blocked or idle, and the runtime surfaces the one that needs you. Anyone who has run six agents in six terminals knows that finding the stuck one is the actual daily problem, and herdr made it the centre of the product instead of a dashboard added later. The second strong part is that agents drive the runtime themselves, through a CLI and socket API. An orchestrating agent can hand work to another pane and wait until that agent is genuinely blocked. Most multi-agent coordination I see is prompts hoping the other agent is done. Here the runtime provides it as a primitive. Now the other side. herdr owns every agent's terminal, so it's the layer best placed to know what each run cost, and the runtime itself records none of it. There's no per-run ledger, no budget and no spend trend. Community plugins have started to fill this in with cost badges on each pane and usage dashboards. A user opened a discussion on the repo about exactly this. A build, review and fix loop re-read about 650k tokens a round for eleven rounds before anyone noticed. Each round looked reasonable, and the runaway only showed across the whole loop. Disclosure, I'm one of the two people who replied in that thread, and no maintainer has weighed in yet. The other gap is in unattended runs, which are a big part of what herdr is for. It flags an agent that's blocked, but one that stops without producing anything looks the same as one that finished its job. herdr itself also keeps no record of what each agent did while you were away, so out of the box you're reading back through each pane's scrollback. The lesson applies to any setup. Put the accounting where the loop lives. A per-turn view can never see an eleven-round runaway, so whichever layer owns the loop has to hold the number. For what it's worth, I put a hard cap on unattended runs and compare daily spend against a median, which is what I argued for in that thread. For anyone running several agents, in herdr or anything else, what do you actually use to see what a whole loop cost?
Herdr is an open-source terminal-based agent multiplexer for managing multiple AI agent sessions with workspaces, tabs, panes, and mouse support. It runs as a background server, allowing detachment and reattachment without losing agent processes.
Herdr is a terminal multiplexer that lets developers run multiple coding agents in separate terminals, on any machine or over SSH, with persistent sessions viewable at a glance.
DHH demonstrates how to manage multiple AI coding agents simultaneously using Herdr, a terminal tool that facilitates parallel agent orchestration on Linux with built-in notifications.
A tweet by @tobi demonstrating how to use herdr, a CLI tool, by launching an agent and running `herdr --skill` to create a sci-fi-style hacker terminal setup.
The author introduces agentwerk, a lightweight Rust crate designed for scaling agent collaboration through a ticket system, aiming to provide a simpler alternative to bloated frameworks like LangChain or AutoGen for human-in-the-loop-free pipelines.