cmux — a native macOS terminal, built on Ghostty, with a vertical sidebar of workspaces for running many AI coding agents at once
Alternative to: Warp, the commercial agent terminal. Like for like it is $0 against $0: Warp Free also lets you bring your own AI. Warp's paid tiers are prepaid AI usage, pay as you go from $20/mo. Also a default: one terminal window per agent.
Cost to run: free for the terminal. The agent you run inside it (Claude Code, Codex and the like) is billed separately by its own vendor. Paid cloud tiers run from $50/mo; a $30/mo Founder's Edition sells early access.
Licence: GPL-3.0-or-later for the macOS app, iOS app and CLI, free for commercial use. The server code is BUSL-1.1 since 2026-09-28 and needs a commercial licence for production use, including self-hosting.
Runs on: the terminal app is macOS 14 Sonoma or later, Apple Silicon or Intel: "macOS only, for now." A separate cmux TUI has Linux and Windows builds.
Requires: a Mac and a coding agent of your own. No Docker, no GPU, no cmux account for the free tier.
Traction: 27,548 stars · 2,424 forks · 19,185 commits · issue and PR numbers reach #16397 · open/closed issues unknown
Liveness: very live — 6,633 commits in the last 30 days; last commit 2026-10-01
Maturity: v0.64.25, the latest stable release, 2026-09-17. Still pre-1.0. The iOS app and remote tmux are labelled beta.
Links: repo · site · pricing · Show HN, 198 points
Figures as of 2026-10-01.
What it does
cmux is a terminal app for the Mac. It runs your shell, and whatever you start in it, in tabs and split panes, the way any terminal does.
The difference is the left edge of the window. Every workspace sits in a vertical sidebar, and each row shows the git branch, the pull request status, the working directory, open ports and the latest notification from whatever is running there. When an agent finishes or needs an answer, its row lights up. Cmd+Shift+U jumps to the newest one.
That is the whole pitch. You run five agents on five projects in one window instead of five windows, and the sidebar tells you which one wants you.
It is not a fork of Ghostty. It uses libghostty as a library for drawing the terminal, and it reads your existing ~/.config/ghostty/config. Around that sits a native Swift app with a scriptable in-app browser, a CLI, a socket API, cmux ssh and a cmux claude-teams command.
The free terminal contains no AI. Claude Code, Codex, Gemini CLI or anything else you run in it brings its own model and its own bill. An early-access "cmux AI" is offered to paying Founder's Edition backers.
What it replaces, and what that costs
The closest product you can buy is Warp, a terminal that sells AI usage on top. Per Warp's own pricing page, where every paid tier is "pay as you go, starting at" the figure shown:
Free — $0, the terminal, limited AI and cloud agents, and "Bring your own AI inference"
Build — from $20/mo monthly, or $18/mo billed annually: 1,500 credits, "$20 of included agent usage at API rates"
Max — from $200/mo monthly, or $180/mo billed annually: 18,000 credits
Business — from $50/user/mo monthly, or $45/user/mo billed annually: up to 25 seats
There is no terminal bill here to stop. The like-for-like comparison is Warp Free at $0 against cmux at $0, and both let you bring your own agent. Warp's Build tier is $20 of prepaid agent usage at API rates, not a fee for the terminal. Anyone who spends it would spend it with their agent's vendor instead. That is why the Quick Facts row says alternative to, not replaces.
Cursor sits further away. It is a full code editor, not a terminal. It comes up here because leaving Cursor for a terminal is the switch this entry was prompted by. Cursor Pro is $20/mo, Pro+ $60/mo, Ultra $200/mo, and Teams Standard $40/user/mo, all monthly. Cursor's annual prices load in the browser and would not render to a scrape, so they are not given here.
What cmux costs instead is nothing, for the terminal. The paid side is a cloud product layered on top:
Free — $0, the open-source macOS terminal, local agents with your own keys
Pro — $50/mo, cloud agents on up to 50 cloud VMs sharing 24 GB RAM and 6 vCPUs, plus the iOS app
Max — $200/mo, up to 50 VMs sharing 64 GB RAM and 16 vCPUs
Team — $60/user/mo, Pro plus central billing
Enterprise — custom, self-hosted or air-gapped
All of it is billed monthly; the pricing page says "Paid plans are billed monthly." The README also links a $30/mo "Founder's Edition" on a Stripe checkout run by Manaflow, Inc., which it describes as early access to cmux AI, the iOS app and Cloud VMs.
Is it still alive?
Very. The repo was created on 2026-01-28 and has 19,185 commits on main. 6,633 of them landed in the last 30 days and 13,554 in the last 90. 223 distinct author emails committed in the past year. The last commit was today.
It is a two-person project in practice. Merging each person's several git identities, Lawrence Chen has 7,512 commits (39.2%) and Austin Wang 7,147 (37.3%). Lawrence's total includes 134 commits from a cmux-lawrence machine identity. The next two contributors have 1,756 and 1,694. An automated account has 532.
Releases come in bursts, not on a schedule. v0.64.22 shipped on 2026-08-03 and v0.64.23 not until 2026-09-14. Three stable releases followed within three days, the last being v0.64.25 on 2026-09-17. That is 14 days ago, against 6,633 commits in 30 days. The work is landing on main and in nightly builds faster than it reaches a stable release.
The download downloads. I pulled the v0.64.25 macOS disk image directly: 225,832,896 bytes. Homebrew carries the same version as a cask.
On Trendshift it was the #1 Swift Repository of the Day on 2026-02-20, and peaked at #5 Repository of the Day across all languages on 2026-02-21.
Open and closed issue counts could not be obtained from the research sandbox.
What people say
The main conversation is the Show HN from 2026-02-19, 224 days ago: 198 points and 77 comments. Reddit is blocked from the research sandbox, so no vote counts from it are claimed.
The interest was immediate:
"Vertical tabs for a terminal emulator seems killer, I'll be trying this out for sure." — mikkupikku
So was the bug report:
"Looks like this could be really cool, but it's a buggy mess. Can't switch top tabs, can't close tabs. Once I lose focus in a tab, I can't ever type again in that terminal tab. Can't switch between the different sidebar tabs, either." — twostorytower
The maintainer replied that it was likely a known issue and that "The latest release (0.57.0) should fix it." The pace was noticed too:
"18 (!) releases in two days. This is some really fast coding." — reconnecting
And one commenter argued against the direction the project has since partly taken:
"My two cents - don’t do it. There’s plenty of terminal editors (and personal opinions about them) to chose from. You will end up reinventing an IDE." — danw1979
Smaller, later threads are about performance. In August, the poster of a thread titled "Cmux SSH Lagging" answered their own question:
"the answer: cmux gui is broken, use cmux-tui in a single tab" — 217
A May post was titled "Why cmux is so lagging when scrolling, also it uses more CPU than Ghostty" and a September one "Ask HN: Why does cmux need 200 settings?" Both are cited by title only; neither drew more than 2 points.
The catch
The terminal app is Mac only. The README says "macOS only, for now." A separate cmux TUI has Linux and Windows builds, and Manaflow ships a nightly Linux build of a different product, cmux Browser, from another repo. There is no stable Windows or Linux version of the app this entry covers.
It is pre-1.0 and moving fast. At 221 commits a day, things change under you. Stable releases lag the code by weeks at a time. The Show HN's first complaint was basic tab handling, and later threads are about SSH lag and scrolling CPU. Session restore, in the project's own docs, "does not checkpoint arbitrary live process state," and scrollback restore is "best effort."
The licence changed three days ago, and it has changed before. A LICENSE file first appeared on 2026-02-14, under AGPL. A commercial dual licence was added in March, and on 2026-03-30 the open-source side moved from AGPL to GPL-3.0, with the commercial option kept. In July the commercial terms were narrowed in scope. On 2026-09-28 the server directories moved to the Business Source License 1.1, which requires a commercial licence from Manaflow for production use, self-hosting included. Each BUSL version converts to GPL-3.0-or-later four years after it is published. The Mac app, iOS app and CLI stay GPL. If you only run the terminal, nothing changed for you. If you planned to self-host the cloud side, it now costs money. The repo also asks contributors to sign a CLA.
The free terminal is the front door to a paid cloud. cmux Pro is $50/mo for cloud VMs that run agents while your laptop is closed, and includes the iOS app. The $30/mo Founder's Edition also lists early access to the iOS app and Cloud VMs. The server code that runs the cloud is the part that is no longer open source. The commit that changed it gives no reason.
"Simple" depends on how far in you go. The sidebar is simple. Someone on HN asked in September why cmux needs 200 settings.
My read
I used Cursor for over a year. It got harder to use, and it got bloated. Somebody put me onto cmux yesterday, and I already like how it works.
It's simple. The left sidebar is the killer feature. I can have multiple projects open at once, easily, instead of a zillion separate screens.
That's a day-one read, not a field report. The real test is a few weeks of daily use with agents running in every workspace. If it survives that, there's a field report in it.
Credits
Built by Lawrence Chen (@lawrencecchen) and Austin Wang (@austinywang) at Manaflow, Inc. (@manaflowai). Abdulaziz Albahar and Leo Li are the next-largest contributors.
Voices quoted: mikkupikku, twostorytower, reconnecting, danw1979 and 217 on Hacker News.
Data: the cmux git history (cloned 2026-10-01), ungh.cc, the cmux README, LICENSE and docs, cmux.com/pricing, warp.dev/pricing, cursor.com/pricing, Trendshift, the Hacker News Firebase and Algolia APIs, and the v0.64.25 release download.