Muster Free and open source

Never keep an
agent waiting.

Muster tells you the moment Claude Code, Codex or Cursor needs you, and lets you answer with one keystroke, from whatever you're doing.

Download for Mac
Muster is a Mac app. Open this page on your Mac to download it, or star it on GitHub to find it later.
Star on GitHub

Notarized by Apple · macOS 14 or later · 2 MB

Two agents asked. Two keystrokes, and you never left your editor. ⌥↩ allows, ⌥⌫ denies, on any screen, notch or not. For Claude Code and Codex, once you turn it on. If Muster quits, your agent just asks the usual way.

⌥↓

See why before you answer.

Press ⌥↓ and the alert unfolds: the agent's reason for asking, the whole command, the file and size of an edit, or every option of a question with its note.

Pick an option with ⌥1, ⌥2 or ⌥3, or fold it away with ⌥↑. The alert always shows which keys it takes.

Muster's alert unfolded on a question from Claude Code: three options, each with the agent's note, answered with Option-1 to Option-3
⌥Tab

Jump to the one that needs you.

Hold ⌥ and tap Tab. Every session is there, the one waiting on you first. Let go and you're in its window, or the terminal it runs in.

2 MBto download
0.4%of one core, with ten agents busy
20 MBof memory
0accounts or trackers
⌃⌥Space

Find any session.

Every session from the last three hours, in one list. Start typing to narrow it down.

Each one shows its tokens and what they would cost at API list prices. On a Max or Pro plan you don't pay that, but it tells you which sessions are the expensive ones.

Made for the Mac.

Muster is a native AppKit app and a 2 MB download. It uses the system's own glass and follows your light or dark appearance.

The switcher, half in dark mode and half in light mode

Opens the right window

Claude's app, the Codex thread, Cursor's Agents window, or the terminal a CLI session runs in.

Remote sessions too

Claude Code sessions that the desktop app runs over SSH show up next to your local ones.

Answers on the banner

Notifications carry Allow and Deny, or the options to a question.

Your shortcuts

Change ⌥Tab and ⌃⌥Space. Muster tells you if another app already uses one.

Raycast and Alfred

muster://next opens the session that needs you most. muster://search opens search.

Unread until you look

A finished session stays marked until you open it.

Your keys stay yours

Muster takes ⌥↩, ⌥⌫ and the arrows only while something on screen needs them, and lets go while you type elsewhere.

Usage limits wait their turn

A session stopped by a usage limit moves out of your way and shows when the limit resets.

What changed, once

After an update, Muster shows what's new a single time. Every release is in the changelog.

Nothing leaves your Mac.

Muster reads the session files your agents already write. An agent's question reaches Muster over localhost, and your answer goes back the same way. There's no account and no analytics, and the update check stays off until you turn it on.

Open source, because
it can say yes for you.

An app that can approve what your agents run should be one you can read. Muster is MIT licensed, and every release passes 213 end-to-end tests that drive the real app before it ships.

Read the code on GitHub

Questions.

How do I know when Claude Code needs me?

Muster counts the sessions waiting on you in the menu bar and shows an alert at the top of your screen. To compare it with Claude Code's own options, read getting notified when Claude Code needs you.

Can I see what the agent wants before I answer?

Yes. Press ⌥↓ on the alert to see the agent's reason, the whole command, or every option of a question with its note, then answer with ⌥↩ or ⌥1 to ⌥9.

Will its shortcuts get in the way of my editor?

No. Muster takes ⌥↩, ⌥⌫, the arrows and the digits only while a prompt or the switcher is on screen, and lets go of them while you type in another app.

Does it work with several sessions at once?

Yes. Every Claude Code, Codex and Cursor session from the last three hours is in one list, with the one that needs you first.

Is it free?

Yes. Muster is open source under the MIT License, with no account.

Does it send my code anywhere?

No. It reads the session files your agents write and talks to them over 127.0.0.1. The only network request is an update check you can turn on.

What if Muster quits while an agent is asking?

The agent falls back to its own prompt, the same as without Muster.

Can it answer Cursor's prompts?

Not yet. Cursor doesn't let another app answer for it, so Muster shows you which chat is waiting and opens it in Cursor.

Which Macs does it run on?

macOS 14 or later, on Apple silicon and Intel.

What's new?

Every release is in the changelog. Muster also shows what changed after each update.

Run more agents
without losing track.

Download for Mac View on GitHub