termdeck
cmux is a terminal app from Manaflow, a Y Combinator company, built for running many coding agents at once. It is a native Swift and AppKit app for macOS that renders with libghostty, Ghostty's terminal library, and reads your Ghostty config for themes and fonts. Any agent that runs in a terminal works: Claude Code, Codex, Gemini CLI, OpenCode, Aider, Amp and others. A sidebar of vertical tabs shows each workspace's git branch, PR status, folder and listening ports, and a pane gets a blue ring when its agent needs you. It adds an in-app browser, a CLI and socket API for scripting, and cmux ssh for remote workspaces. The app is free and GPL licensed; paid plans add Cloud VMs and an iOS app.
Comparison
Termdeck vs cmux: every machine, not one Mac.
cmux is a native Mac terminal for watching several coding agents side by side; Termdeck is a browser board for every Claude Code, Codex and Grok session on every machine you connect.
Context
What cmux is
Side by side
cmux vs Termdeck, feature by feature
| Feature | cmux | Termdeck |
|---|---|---|
| What it is | Native terminal app on your Mac | Web UI in the browser, small agent on each machine |
| Agent CLIs supported | Any terminal agent: Claude Code, Codex, Gemini CLI, OpenCode, Aider, Amp and more | Claude Code, Codex and Grok; engine picked per chat |
| Platforms | macOS app; Linux x64 nightly builds; no Windows build | Agents on macOS, Linux and Windows; drive from any browser |
| When an agent needs you | Blue ring on the pane, lit sidebar tab, notification panel | "Needs you" badge in the sidebar, Web Push to your phone |
| Tool-call approvals | The agent's own prompt, answered in the pane | Allow / deny card with a risk badge, answerable from a phone |
| Other machines | cmux ssh opens a workspace on a remote host | Every connected machine in one sidebar; the agent dials out, no inbound ports |
| From your phone | iOS app in beta on TestFlight, on paid plans | Installable PWA in any phone browser |
| Closing the window | Relaunch restores layout, folders and scrollback; live processes stop | The run keeps going on the machine; reopen and catch up |
| The pane grid | Splits, tabs and workspaces, rendered natively | Terminals page: chats tiled tmux style, from every machine |
| Price | App free; Pro $40/mo yearly or $50 monthly adds Cloud VMs and iOS | 14-day free trial, then $9.99/mo |
Verified 10 October 2026 against cmux.com, its pricing page and the GitHub README. Rows we could not check on the cmux side, such as diff review and multi-account switching, are left out. cmux moves fast; tell us if a row is out of date.
Straight answer
Where cmux wins
If all your agents run on the Mac in front of you, cmux is the better tool. It is a native local app on Ghostty's renderer, so panes are as fast as a terminal gets, and it works with any agent CLI rather than three. It puts a real browser and a scriptable socket API beside your agents, which Termdeck does not offer, and the app itself costs nothing.
The delta
Where Termdeck wins
Every machine, any OS
cmux sees what you open in it on one Mac, plus hosts you reach over SSH. Termdeck's agent runs on macOS, Linux and Windows boxes and publishes every session on each one, including chats started in a plain terminal, to a single sidebar you open from any browser.
Runs outlive the window
A cmux relaunch brings back the layout, not the processes. In Termdeck the agent holds the run on the machine, so closing the tab, losing wifi or sleeping your laptop does not stop it; you come back and read what happened.
Approvals on the phone you have
cmux's phone app is an iOS beta on paid plans. Termdeck installs as a web app on any phone, pushes when a tool call is waiting, and the notification opens the chat it came from. It can also switch between several Claude or ChatGPT logins mid chat when one hits a rate limit.
Questions
Termdeck vs cmux, answered
What is cmux?
cmux is a terminal app from Manaflow for running several AI coding agents at once. It is a native macOS app built on libghostty, with vertical tabs that show each workspace's branch and ports, a ring around any pane whose agent needs input, an in-app browser, and a CLI and socket API for scripting.
Is cmux free?
The app is. The macOS terminal is free and open source under GPL-3.0-or-later. Paid plans start at $40 a month billed yearly ($50 monthly) and add Cloud VMs and the iOS app; Team is $60 per user a month. Termdeck has a 14-day free trial, then costs $9.99 a month.
Does cmux work on Linux or Windows?
The GitHub README calls cmux macOS only for now. cmux.com also offers Linux x64 builds from the nightly channel, as a .run installer or a .deb package. There is no Windows build. Termdeck's agent runs on macOS, Linux and Windows, and you drive it from any browser.
What is the difference between cmux and tmux?
cmux is a GUI terminal app: it draws the panes, tabs and notifications on your Mac. tmux is a multiplexer that runs inside any terminal and keeps processes alive when you detach or your SSH link drops. cmux restores layout and scrollback after a relaunch but not live processes, and it can attach to remote tmux sessions, so many people run both.
Is cmux a fork of Ghostty?
No. cmux is its own Swift and AppKit app that uses libghostty, Ghostty's terminal library, for rendering. It reads your existing Ghostty config for themes, fonts and colors, so a Ghostty setup carries over.
Keep reading
Related
Termdeck vs tmux
The multiplexer cmux is usually measured against: what keeping a session alive covers, and what an agent still needs on top.
Termdeck vs Conductor
Another way to run Claude Code and Codex sessions in parallel, compared against a board that spans machines.
The Termdeck interface
The sidebar, tabs, board and the Terminals page that tiles chats from every machine in one grid.