cmux/web/app/blog/show-hn-launch/page.tsx

import type { Metadata } from "next";
import Image from "next/image";
import Link from "next/link";
import { Tweet } from "react-tweet";
import { DownloadButton } from "../../components/download-button";
import { GitHubButton } from "../../components/github-button";
import starHistory from "./star-history.png";

export const metadata: Metadata = {
  title: "Launching cmux on Show HN",
  description:
    "cmux launched on Hacker News, hit #2, went viral in Japan, and people started building extensions on the CLI. Here's what happened.",
  keywords: [
    "cmux",
    "Show HN",
    "Hacker News",
    "terminal",
    "macOS",
    "Ghostty",
    "libghostty",
    "AI coding agents",
    "Claude Code",
    "Codex",
    "launch",
    "vertical tabs",
    "notification rings",
  ],
  openGraph: {
    title: "Launching cmux on Show HN",
    description:
      "cmux launched on Hacker News, hit #2, went viral in Japan, and people started building extensions on the CLI.",
    type: "article",
    publishedTime: "2026-02-21T00:00:00Z",
    url: "https://cmux.dev/blog/show-hn-launch",
  },
  twitter: {
    card: "summary",
    title: "Launching cmux on Show HN",
    description:
      "cmux launched on Hacker News, hit #2, went viral in Japan, and people started building extensions on the CLI.",
  },
  alternates: {
    canonical: "https://cmux.dev/blog/show-hn-launch",
  },
};

export default function ShowHNLaunchPage() {
  return (
    <>
      <div className="mb-8">
        <Link
          href="/blog"
          className="text-sm text-muted hover:text-foreground transition-colors"
        >
          &larr; Back to blog
        </Link>
      </div>

      <h1>Launching cmux on Show HN</h1>
      <time dateTime="2026-02-21" className="text-sm text-muted">February 21, 2026</time>

      <p className="mt-6">
        We posted cmux on{" "}
        <a href="https://news.ycombinator.com/item?id=47079718">Show HN</a>{" "}
        on Feb 19:
      </p>

      <blockquote className="border-l-2 border-border pl-4 my-6 text-muted space-y-3 text-[15px]">
        <p>
          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&apos;s
          notification body is always just &quot;Claude is waiting for your
          input&quot; with no context, and with enough tabs open, I couldn&apos;t
          even read the titles anymore.
        </p>
        <p>
          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.
        </p>
        <p>
          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.
        </p>
        <p>
          The in-app browser has a scriptable API. 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.
        </p>
        <p>
          Everything is scriptable through the CLI and socket API: create
          workspaces/tabs, split panes, send keystrokes, open URLs in the browser.
        </p>
      </blockquote>

      <p>
        At peak it hit #2 on Hacker News. Mitchell Hashimoto shared it:
      </p>

      <Tweet id="2024913161238053296" />

      <p>
        My favorite comment from the{" "}
        <a href="https://news.ycombinator.com/item?id=47079718">HN thread</a>:
      </p>

      <blockquote className="border-l-2 border-border pl-4 my-6 text-muted space-y-3 text-[15px]">
        <p>
          Hey, this looks seriously awesome. Love the ideas here, specifically:
          the programmability (I haven&apos;t tried it yet, but had been
          considering learning tmux partly for this), layered UI, browser w/
          api. Looking forward to giving this a spin. Also want to add that I
          really appreciate Mitchell Hashimoto creating libghostty; it feels
          like an exciting time to be a terminal user.
        </p>
        <p>Some feedback (since you were asking for it elsewhere in the thread!):</p>
        <ul className="list-disc pl-5 space-y-1">
          <li>
            It&apos;s not obvious/easy to open browser dev tools (cmd-alt-i
            didn&apos;t work), and when I did find it (right click page →
            inspect element) none of the controls were visible but I could see
            stuff happening when I moved my mouse over the panel
          </li>
          <li>
            Would be cool to borrow more of ghostty&apos;s behavior:
            <ul className="list-disc pl-5 mt-1 space-y-1">
              <li>
                hotkey overrides – I have some things explicitly unmapped /
                remapped in my ghostty config that conflict with some cmux
                keybindings and weren&apos;t respected
              </li>
              <li>
                command palette (cmd-shift-p) for less-often-used actions +
                discoverability
              </li>
              <li>
                cmd-z to &quot;zoom in&quot; to a pane is enormously useful imo
              </li>
            </ul>
          </li>
        </ul>
        <p className="text-xs">
          —{" "}
          <a href="https://news.ycombinator.com/item?id=47083596" className="hover:text-foreground transition-colors">
            johnthedebs
          </a>
        </p>
      </blockquote>

      <p>
        Surprisingly, cmux went semi-viral in Japan!
      </p>

      <Tweet id="2025129675262251026" />

      <p>
        Translation: &quot;This looks good. A Ghostty-based terminal app
        designed so you don&apos;t get lost running multiple CLIs like Claude
        Code in parallel. The waiting-for-input panel gets a blue frame, and
        it has its own notification system.&quot;
      </p>

      <p>
        Another exciting thing was seeing people build on top of the cmux
        CLI. sasha built a pi-cmux extension that shows model info, token
        usage, and agent state in the sidebar:
      </p>

      <Tweet id="2024978414822916358" />

      <p>
        Everything in cmux is scriptable through the CLI: creating workspaces,
        sending keystrokes, controlling the browser, reading notifications.
        Part of the cmux philosophy is being programmable and composable, so
        people can customize the way they work with coding agents. The
        state of the art for coding agents is changing fast, and you don&apos;t
        want to be locked into an inflexible GUI orchestrator that can&apos;t
        keep up.
      </p>

      <p>
        If you&apos;re running multiple coding agents,{" "}
        <a href="https://github.com/manaflow-ai/cmux">give cmux a try</a>.
      </p>

      <div className="my-6">
        <Image
          src={starHistory}
          alt="cmux GitHub star history showing growth from near 0 to 900+ stars after the Show HN launch"
          placeholder="blur"
          className="w-full rounded-xl"
        />
      </div>

      <div className="flex flex-wrap items-center justify-center gap-3 mt-12">
        <DownloadButton location="blog-bottom" />
        <GitHubButton />
      </div>
    </>
  );
}