Herdr vs cmux: a terminal runtime or a Mac terminal app for coding agents, and where Caprock fits

Herdr and cmux solve the same problem — many coding agents at once, and knowing which one needs you — in two shapes. Herdr is a runtime that runs inside the terminal you already use, on macOS, Linux and native Windows, and keeps your agents running when you close it or lose SSH. cmux is a native macOS terminal app on libghostty, with a built-in browser, notification rings, an iOS app in beta and paid cloud machines. Both are cockpits: each shows the agents in its own panes, and neither shows what they cost.

What each one is

• Herdr (Apache-2.0) is one Rust binary: workspaces, tabs and panes, each agent in a real terminal, with a sidebar that reads every pane's screen and marks it idle, working or blocked. A background server keeps the terminals running when the client closes. It lists 18 agents as supported, 5 of which report their own state, and has an API to read, send to, wait on, split and attach panes. It had 46,170 GitHub stars on 27 October 2026 and took a $6M seed led by Bessemer on 8 September 2026; Herdr Cloud is a waitlist.
• cmux (GPL-3.0-or-later for the app, BUSL-1.1 for its server software) is a macOS terminal built in Swift and AppKit on libghostty. It reads your Ghostty config, draws vertical tabs, puts a blue ring on a pane whose agent needs you, and has a scriptable browser pane. cmux ssh opens a workspace on a remote host.

Herdr vs cmux, side by side

What Herdr's own comparison leaves out

Herdr's comparison page groups cmux with Warp and marks detach, reattach and SSH as only partial for them. cmux's own docs now describe cmux ssh and an iOS app, and its changelog for release 0.65.0 (5 October 2026) adds Running, Needs input and Idle states for Claude Code and Codex on SSH hosts. Read both makers' pages, not one about the other.

What each one sees

Both see the agents in their own panes. Herdr reads each pane's screen, and its docs say agents it does not recognise "just show up as plain terminals"; a user whose Claude Code is wrapped by nix wrote that "herdr agent list is empty, even while the agent runs normally" (#803, +13). cmux tracks an agent from the terminal it started, by a token it mints at launch, so one running in Terminal, iTerm or tmux outside cmux is not listed; an open bug with 44 reactions reads "Shows 'Running' when not actually running … 'Needs Input' doesn't show up when it should" (#1027, +44, open since 6 March 2026). Neither shows cost or limits on your own machine; cmux shows token usage per Cloud machine on its paid plans. Everything in this paragraph was read 27 October 2026.

What cmux sells

Pro, $50 a month or $480 a year, adds cloud machines and the iOS app; Max, $200 a month, larger machines; Team, $60 a seat a month, is Pro per seat with shared cloud machines and model accounts and central billing; Enterprise adds SSO, audit logs and self-hosted cloud, by contact (its pricing, read 27 October 2026). Cost per repository or per person for the team is not in its docs. Herdr sells nothing: its runtime "stays open", and Herdr Cloud, connecting your machines without SSH, is a waitlist with no price or date.

Where Caprock fits

Caprock is the ledger people keep beside either. It records every agent session on the machine whether or not it started it: the claude from your own terminal live, Codex, OpenCode, DeepSeek Harness and Hermes Agent from the history they write. Each turn is priced at list price per repository, each pull request shows its checks and what the agents spent on it, and Claude's and Codex's windows sit beside the cost with a warning before the limit. For a team, a server the team hosts adds the same up by repository, pull request and release, with no prompts in the payload. Its tabs and split panes, and a phone paired by QR code with no account, are how you live with it. Every dollar Caprock shows is an estimate at API list price, as Claude Code's own /usage is: not a bill, and on a flat plan not money saved.

What Caprock does not do

• Not the cloud, not CI. Sessions that run in a vendor's cloud or inside CI are not observed; Caprock sees the machines it is installed on.
• No SSH remotes, no cloud machines. It reaches only your other computers that run Caprock, through its relay.
• Not inside your terminal. It renders its own terminals, in its own window; or keep your own terminal and let it read.
• No code editor. Files open read-only in a tab; you edit in your own editor.
• No native phone app. The phone uses its browser, which can be added to the home screen.

Which to pick

• Herdr — you live in a terminal, use several machines over SSH, or are on Windows. Weighing it against an app instead: Orca vs Herdr.
• cmux — you are on a Mac and want one native app with a browser in it, or would pay for cloud machines and seats.
• Caprock — you want the ledger beside either: every agent on the machine, who is waiting on you, each limit, and what each pull request cost. Install it.