↓ Skip to main content
tomrochette.com
  1. Agents/

cmux

Author
glm-5.3, glm-5.3-flash
History / Edit / PDF / EPUB / MD
Created: / Updated: / Status: finished / Readability: 3 / 5 minutes read (~862 words)
agent-curated 173 fully-ai-generated 263 llm=glm-5.3 170 llm=glm-5.3-flash 178 macos 2 orchestration 16 parallel-agents 5 research-note 148 terminal 7
Table of Contents

cmux is Manaflow’s open-source macOS terminal built on libghostty for running many coding agents in parallel, with vertical tabs, workspaces, notification rings, and an open-core cloud tier. Facts below verified as of 2026-09-13.

cmux’s real product is attention routing, not multiplexing, and its real business is cloud execution: the terminal is the free, GPL-3.0 funnel, and the subscription is where the company actually lives.

What it is
#

A native macOS terminal (built on libghostty, not an Electron app and not a Ghostty fork) whose features target the many-agents-at-once workflow: vertical and horizontal tabs, workspaces, split panes, notification rings around panes that need you, a notification panel that jumps to the most recent unread agent, and an in-app browser with a scriptable API ported from agent-browser. It is programmable through a socket API and a cmux notify CLI, ships local session history, and runs Claude Code, Codex, Gemini, and any CLI agent on your own keys. A Pro subscription adds Cloud VM agents and the iOS app; the CodeRouter pitch that was on the pricing page in August has since disappeared from it.

Status
#

Active and remarkably fast. About 27k stars and 2.3k forks as of 2026-09-13, created January 28, 2026, with commits landing the day of verification. The launch thread counted 18 releases in two days; the project is at v0.64.x with a nightly channel. Three contributors dominate the history (about 5.2k, 3.8k, and 1.2k contributions), so this is a small funded team (Manaflow, Inc.) moving very quickly, not a broad community.

Strengths
#

  • Notification rings and the unread panel solve the actual pain of parallel agents, knowing which terminal is waiting for you, better than any tmux setup.
  • libghostty makes it a real native terminal with real performance, and the maintainer is responsive (launch-thread bugs fixed within releases).
  • The scriptable socket API and notify CLI mean agents themselves can drive it, and third parties already teach Claude Code to do exactly that.
  • The free tier is the full terminal: every CLI agent, BYOK, notifications, browser panels, no metering.

Cautions
#

  • macOS only, and the client is GPL-3.0-or-later (which GitHub labels “Other”), so copyleft-policy teams should check before adoption.
  • Open-core: cloud execution sits behind Pro at $40/month (billed yearly), so the roadmap’s center of gravity is the subscription, not the terminal.
  • The pace is a risk profile: 0.x versions, a nightly channel, and a launch-era bug list mean churn.
  • An August 2026 thread reports whole-app freezes of 2-10 seconds with SSH sessions open, so remote-heavy workflows should test first.
  • Name collisions are everywhere: craigsc/cmux (“tmux for Claude Code”, MIT, about 602 stars), a separate October 2025 Show HN “Cmux, Coding Agent Multiplexer” GUI, and an unrelated Go connection multiplexer; search carefully before citing.

Pricing
#

Free $0: the full terminal, any CLI agent BYOK, notifications, browser panels, socket API, local history. Pro $40/month billed yearly ($50 month-to-month): cloud agents on isolated VMs, capped at up to 50 Cloud VMs per user with 24 GB RAM and 6 vCPUs shared across all of them, as of 2026-09-13 (the page churned back to shared-pool totals from the per-VM resources with a 256 GB disk ceiling it showed on 2026-09-09, and it had shown different shared-pool totals through 2026-09-05), plus unlimited workspaces, the iOS app, and email support. Team $48/user/month billed yearly ($60 month-to-month) adds centralized billing and priority support; Enterprise adds self-hosted, even air-gapped, cloud execution, SSO/SAML, audit logs, and SOC 2, as of 2026-09-13.

Compared to
#

  • dmux: tmux-based and cross-platform; pick dmux off macOS, cmux for notifications.
  • Claude Squad: free AGPL tmux manager; lighter, rougher, no cloud ambitions.
  • Vibe Kanban: kanban abstraction over agents versus staying in the terminal metaphor.

Bottom line
#

Recommended for macOS engineers whose bottleneck is attention across many CLI agent sessions and who want that solved in a real terminal. Not for Linux or Windows users, copyleft-restricted shops, or anyone who needs a stable 1.0 interface.

Changes
#

  • 2026-08-24 - Created in the Orchestration category after an owner request, covering manaflow-ai/cmux and disambiguating two same-named products.
  • 2026-09-02 - Pricing packaging changed, CodeRouter removed and unlimited active cloud VMs added.
  • 2026-09-04 - Cloud VM disk cap cut from 200GB to 32GB.
  • 2026-09-05 - Pricing restructured again to a shared pool (5 vCPU, 20 GB, 200 GB) with VMs starting at 8 GB/32 GB.
  • 2026-09-06 - Pricing page dropped the shared-pool cloud spec for per-VM resources with a 256 GB disk ceiling.
  • 2026-09-10 - Pricing page reverted to shared-pool phrasing (24 GB RAM, 6 vCPU shared).

See also
#

References
#