cmux
Ghostty-based terminal with vertical tabs and notifications
Details
- External ID
- 47079718
- Source
- HN
- Company
- —
- Product
- cmux
- Website domain
- github.com
- Launched
- Feb. 19, 2026
- Cohort
- —
- Upvotes
- 198
- Upvotes percentile
- 0.9454177897574124
- Tags
- —
- Fetched at
- Sept. 7, 2026, 9:25 p.m.
- Updated at
- Sept. 7, 2026, 9:25 p.m.
Description
I run a lot of Claude Code and Codex sessions in parallel. I was using Ghostty with a bunch of split panes, and relying on native macOS notifications to know when an agent needed me. But Claude Code's notification body is always just "Claude is waiting for your input" with no context, and with enough tabs open, I couldn't even read the titles anymore.I tried a few coding orchestrators but most of them were Electron/Tauri apps and the performance bugged me. I also just prefer the terminal since GUI orchestrators lock you into their workflow. So I built cmux as a native macOS app in Swift/AppKit. It uses libghostty for terminal rendering and reads your existing Ghostty config for themes, fonts, colors, and more.The main additions are the sidebar and notification system. The sidebar has vertical tabs that show git branch, working directory, listening ports, and the latest notification text for each workspace. The notification system picks up terminal sequences (OSC 9/99/777) and has a CLI (cmux notify) you can wire into agent hooks for Claude Code, OpenCode, etc. When an agent is waiting, its pane gets a blue ring and the tab lights up in the sidebar, so I can tell which one needs me across splits and tabs. Cmd+Shift+U jumps to the most recent unread.The in-app browser has a scriptable API ported from agent-browser [1]. Agents can snapshot the accessibility tree, get element refs, click, fill forms, evaluate JS, and read console logs. You can split a browser pane next to your terminal and have Claude Code interact with your dev server directly.Everything is scriptable through the CLI and socket API – create workspaces/tabs, split panes, send keystrokes, open URLs in the browser.Demo video: https://www.youtube.com/watch?v=i-WxO5YUTOsRepo (AGPL): https://github.com/manaflow-ai/cmux[1] https://github.com/vercel-labs/agent-browser
Enrichment
- Theme
- utilities for Claude and Claude Code
- Vertical
- Horizontal
- Function
- Dev tools
- Audience
- Developer
- AI stance
- Not AI
- Project type
- Commercial product
- Normalized one-liner
- terminal emulator with vertical tabs
- Manually corrected
- False
Could you build this?
Partial Building a terminal UI wrapper or multiplexer with tabs is doable, but embedding and customizing low-level terminal emulators (Ghostty/libghostty in Zig/Metal/Cocoa) and parsing real-time PTY state requires systems UI expertise.
What it would actually take: The stack likely uses macOS native APIs (Swift/AppKit) or Zig/Rust binding directly into Ghostty's core rendering engine (Metal-accelerated terminal emulation). The difficult technical pieces include cross-process pseudo-terminal (PTY) management, escape sequence parsing, terminal buffer inspection to infer CLI tool status, and macOS native notification hooks. Requires systems-level Cocoa/Metal and terminal protocol domain experience.
Discussion
20 comments analyzed.
Competitors mentioned: WaveTerm, tmux-based solutions (Tabby), WezTerm, iTerm2, Ghostty
Concerns raised: Risk of reinventing an IDE instead of solving specific problems, WaveTerm has performance issues (laggy, Electron-based), Unclear what pre-launch status means
Feature requests: Horizontal scrolling for infinite terminal appending instead of squishing panels, Disable automatic reordering of tab groups by recency, Start in dashboard mode by default to show boxes on startup, Zoom behavior should keep tab bar visible and not zoom out when making splits, SSH session context preservation when opening new workspaces with proxy support
Competitors
Other products that read as similar to this one — 267 launches clear the similarity bar, closest 8 shown.
Attention rank: #24 of 268 (itself plus its competitors, highest first — normalized so YC and Product Hunt are compared fairly).
Launched 98 days after the earliest competitor.
- Deckard, Claude-first terminal manager · hn · 2026-04-02 · 7 upvotes · similarity 0.61
- Alien Desk · ph · 2026-09-29 · 2 upvotes · similarity 0.57
- I built a tool to un-dumb Claude Code's CLI output (Local Log Viewer) · hn · 2026-02-13 · 69 upvotes · similarity 0.52
- Nori CLI, a better interface for Claude Code (no flicker) · hn · 2026-01-14 · 37 upvotes · similarity 0.51
- A terminal glued to the macOS dock · hn · 2026-08-06 · 55 upvotes · similarity 0.48
- GitHub · ph · 2026-09-30 · 2 upvotes · similarity 0.48
- A usable macOS sandbox for Claude Code · ph · 2026-09-30 · 1 upvotes · similarity 0.46
- Computer Use in Claude Code · ph · 2026-03-31 · 442 upvotes · similarity 0.45
Other launches for this product
Same idea, different domain
Nobody's really built a dev tools tool for Sales yet.