cmux alternative built around Claude Code and Codex

cmux and omux want the same thing: a Mac terminal that makes running many coding agents bearable. Both are native Swift apps, both are free and open source, and both light up when an agent needs you.

They differ in what they're built around. cmux is a general terminal, rendered by libghostty, with workspaces, split panes, SSH, an in-app browser with an automation API, and a CLI and socket API that scripts can drive. omux is narrower on purpose: it's a session manager for Claude Code and Codex, and it reads their own signals to show status, permissions, subagents and usage limits.

Download omux for macOS About cmux

At a glanceomuxcmux

Native macOS app✓✓

Status from the agents' own protocols✓✕

Allow/Deny buttons✓✕

Subagent transcripts✓~

Worktrees with PR merge and cleanup✓~

Split panes✓✓

SSH workspaces✕✓

CLI and socket API✓✓

Free and open source✓✓

5 MBnative Swift app, no Electron
0accounts, credits or telemetry
6sessions side by side per project
MITfree and open source

omux with eight projects in the sidebar, a Claude Code conversation in the transcript view, a Codex session waiting on Allow or Deny, and the Changes panel showing a diff — omux: projects and sessions on the left, the agent in the middle, its diff on the right. The session that needs you shows Allow and Deny.

Where the agent lives

cmux

Native Mac window on libghostty

↓

Workspaces, splits and notifications

↓

Your own agents

omux

The native agentic development platform for the Mac, about 5 MB

↓

Claude CodeClaude CodeCodexCodexshell

↓

The real Claude Code and Codex, on your own plans

working needs you done

Side by side

	omux	cmux
Runs on	macOS	macOS
Built with	SwiftUI and SwiftTerm	Swift and AppKit on libghostty; reads your Ghostty config
Organizing work	Projects, each with sessions; optional worktree per session	Workspaces with vertical tabs showing branch, directory, ports and PR status
Agent needs attention	Status from Claude Code's and Codex's own protocols: working, needs you, done, and what it's doing	Notification rings and a notification panel, fed by OSC 9/99/777 and the cmux notify CLI
Answer a permission prompt	Allow and Deny buttons in the sidebar and header; Codex approvals show the command	Jump to the pane
Subagents	Listed per session with transcripts; Codex child agents too	Claude Code Teams mode, teammates as native splits
Conversations after a restart	Each session resumes its exact Claude or Codex conversation	Layout, directories and saved session ids restored; supported agents resume
Pull requests	PR status per worktree session, create, merge, clean up	PR status shown in the sidebar
Side panels	Files, Changes (diff with review notes sent to the agent) and Browser	In-app browser with a scriptable automation API
Usage limits	Claude and Codex plan limits in the sidebar	✕
Split panes	✓ split right and down on a per-project canvas, dividerless, layouts saved	✓ right and down
Remote machines over SSH	✕	✓ cmux ssh
Scripting	✓ omux CLI over a local socket, scoped so an agent can only steer sessions it started	CLI and Unix socket API
Updates	In-app, signed, notarized	In-app via Sparkle, DMG and Homebrew
License	MIT	GPL-3.0 for the app

A closer look at omux

A Codex session asking to run npm outdated, with Allow and Deny in the transcript and in the sidebar — Every approval is a card. Allow or Deny from the transcript or the sidebar, or tell the agent what to do instead.

A Codex session's reply with a code block, next to the file it changes — Codex replies stream in as they're written, with code blocks you can copy and files you can open.

A Claude Code session and a Codex session side by side in one project, with the diff on the right — Sessions side by side: drop one onto another to split the pane.

The Files panel editing server.ts next to the conversation, with ⌘S to save — Edit files in the Files panel, with syntax colors and ⌘S to save, while the agent keeps working.

The agent and model picker: Claude Code models and Codex models in one menu — Switch a session between Claude Code and Codex, or change the model, from the compose box. The conversation is handed over.

Pick cmux if

You want SSH workspaces, a browser automation API, or Ghostty rendering.
You already use Ghostty and want its rendering and config.
You run agents beyond Claude Code and Codex and want them all treated the same way.

Pick omux if

Your sessions are Claude Code and Codex, and you want status, permissions and subagents read from the agents themselves rather than from notifications.
You want a worktree per session with the pull request's state, the diff and review notes right there.
You like a smaller, MIT-licensed app whose CLI is scoped so agents can only touch what they started.

What omux does for every session

Projects with sessions under them, in a sidebar
Shows whether each agent is working, needs you or is done
Allow or Deny an agent's permission request without switching to it
Lists a session's subagents and opens their transcripts
Resumes each Claude Code and Codex conversation after a relaunch
Git worktree per session, with pull request status and merge
Files, Changes (diff with review notes) and Browser panels
Claude and Codex plan usage limits in the sidebar
Split panes: up to six sessions side by side per project, layouts saved
An omux command line: list, status, send, new, close and wait on sessions
macOS notifications with sound

Questions

Which is more mature?

cmux has a broader feature set and a larger community. omux is newer and focused; check both changelogs and pick the one whose direction matches how you work.

Can omux read Ghostty themes?

No. omux has its own themes and font settings. cmux reads your Ghostty configuration.

Does omux have a CLI?

Yes, since 0.9: omux list, status, screen, send, new, close and wait, over a per-launch Unix socket. It is scoped: a session can only steer sessions it started, and the whole thing can be switched off in Settings.

Also compared: Terminal alternative, tmux alternative, Warp alternative, herdr alternative, T3 Code alternative, VS Code alternative, Cursor alternative, Antigravity alternative, Devin alternative. Facts about cmux come from its public documentation as of 2026-11-06; if something is out of date, open an issue.