Muster: Open-Source Mac App for Managing Claude, Codex, and Cursor Sessions
Muster is an open-source Mac menu bar app that streamlines interactions with Claude Code, Codex, and Cursor by providing quick access to essential features through a compact interface.
Overview of Muster's Functionality
Muster is an open-source Mac menu bar app designed to streamline interactions with Claude Code, Codex, and Cursor. It provides quick access to essential features through a compact interface, allowing users to manage multiple sessions efficiently. By clicking the menu bar icon, users can open the appropriate window—whether it's Claude's app, Codex's thread, Cursor's Agents window, or a terminal for CLI sessions. This functionality enhances productivity by reducing the need to switch between applications manually. Additionally, Muster supports remote sessions, such as Claude Code sessions running over SSH, which appear alongside local sessions for seamless management. The app is built with a focus on simplicity and integration, making it a useful tool for developers and researchers who frequently use these AI-powered coding assistants.
User Experience and Privacy Features
The Muster app for Claude, Codex, and Cursor prioritizes user experience and privacy by minimizing intrusive behavior. It captures keyboard shortcuts such as ⌥↩, ⌥⌫, the arrows, and digits only when a prompt or the switcher is visible on screen, releasing them immediately when the user types elsewhere. This ensures that the app does not interfere with other tasks or applications. According to the developers, there is no account system, no analytics, and the update check is disabled by default, giving users full control over their data and preferences. These features align with the app’s open-source philosophy, reinforcing the principle that 'your keys stay yours.' The design emphasizes privacy by default, with no tracking or data collection, and users can choose to enable updates manually if desired.
Technical Implementation and Integration
The technical implementation of the open-source Mac menu bar app for Claude, Codex, and Cursor relies on reading session files generated by these agents. These files are stored in a read-only format and contain questions and answers exchanged over the local network address 127.0.0.1. The app, named Muster, accesses these session files to provide a unified interface for users. According to the developers, Muster communicates with the agents through the same local network connection, ensuring seamless integration without requiring changes to the agents' core functionality. If an agent is unable to interact with Muster, it reverts to its default prompt, maintaining consistency with its standard behavior. This approach allows for minimal disruption to existing workflows while offering users additional control and visibility into agent interactions.
Sources and reporting notes
Based on published source material. No independent hands-on testing is claimed.
