The laptop lid shouldn’t kill your work
A video demonstration shows Rex, a new terminal from the creator of Ghostty, running Anthropic’s Claude on a remote machine. The user closes a MacBook Pro, reopens it, and Claude continues processing without interruption. This functionality bypasses traditional tools like tmux or SSH.
This capability addresses a fundamental limitation in conventional terminal emulators. Typically, a terminal window directly owns the processes it launches. Quitting the application, closing a laptop lid, or losing a network session terminates any long-running command-line interface (CLI) jobs.
Developers often rely on workarounds like tmux to detach and reattach sessions, allowing processes to persist in the background. However, tmux operates as a separate terminal emulator, introducing overhead, distinct keybindings, and a complex configuration.
Rex aims to eliminate this friction. It employs a client-server architecture where a lightweight background server manages process lifecycles and persistently holds sessions. The Rex application functions solely as a display client, connecting to this server.
This design enables developers to initiate long-running tasks, such as autonomous coding agents or complex build processes, and disconnect without fear of interruption. The work continues on the remote machine, accessible upon returning, eliminating the need to keep a laptop awake as a makeshift server.
Rex keeps the session, not the window
Rex’s design separates the terminal’s display from its underlying processes. A lightweight background server manages PTY sessions and running programs, while the Rex application functions purely as a graphical client. Closing the application interface or suspending a laptop does not terminate active work; the server maintains the session, ready for reconnection.
This architecture differs from tmux, which also preserves sessions but renders program output through its own terminal layer. tmux reads program output, draws a text-based representation, and then sends that to the user’s actual terminal. This introduces an additional layer of emulation, requiring users to learn tmux’s specific key commands and configuration for features like scrolling, text selection, and pane management.
Rex, by contrast, uses the libghostty engine to draw everything natively. The application connects to the server as a view, ensuring that panes are real application panes and that scrolling and text selection function as they would in any macOS application.
The design positions Rex as a multiplexer with a native GUI, not merely a faster terminal emulator. It offers persistent sessions and remote capabilities within a single application, integrating directly with Tailscale for secure access. This approach enhances user experience without claiming to render established tools like SSH or tmux obsolete; instead, it addresses their architectural limitations for modern workflows.
Ghostty’s engine meets Tailscale’s network
Rex’s interface renders using libghostty, the reusable engine from the Ghostty terminal emulator. This integration allows panes, scrolling, and text selection to behave as native application features rather than emulated screen output. The client-server architecture ensures that the application window functions purely as a view, detaching the display from the process lifecycle.
Remote access to machines integrates Tailscale directly, enabling connections to devices on a mesh network without manual SSH key management or tunnel configuration. This identity-based access streamlines workflows for developers operating across multiple environments.
The system also includes a standalone rex CLI, supporting automation via JSON output for programmatic layout management. Configuration is available through Lua, offering flexibility for user customization. Additionally, Rex features process awareness, which can surface relevant context—such as active port bindings or the icon for an active AI agent like Claude Code—directly within tab headers. For further details on Superlogical's developer tooling, visit Superlogical - The Multiplexer for All Work.
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A compelling tmux alternative—with trade-offs
Rex primarily targets developers requiring persistent sessions, native macOS interaction, and integrated monitoring for agents like Claude Code. Its client-server architecture and Ghostty-powered rendering differentiate it from traditional terminal multiplexers.
Multiplexers like tmux offer broad compatibility across Unix-like systems and operate without a dedicated GUI or Tailscale. It remains a lightweight option for servers and established workflows where its text-based rendering and keyboard-driven interface are acceptable.
Rex aims to provide a more integrated experience for macOS users, leveraging libghostty for native-feeling panes and scrolling. This design allows users to close their laptop lids or disconnect from the app without terminating active processes, a common frustration with standard terminals.
The current public beta for Rex is distributed as a macOS application. Readers should check Superlogical for the latest availability and platform support. Rex’s long-term viability hinges on whether its convenience and native user experience outweigh the ecosystem reach of established tools like tmux.
Frequently Asked Questions
What is Rex?
Rex is a terminal and multiplexer from Mitchell Hashimoto’s company, Superlogical. It keeps sessions running in a background server while its app provides the interface.
How is Rex different from tmux?
Both preserve sessions, but Rex uses a native graphical client powered by the Ghostty engine, while tmux renders a terminal interface inside your terminal.
Can Rex connect to remote machines?
Rex includes Tailscale integration for connecting to machines on a Tailscale network. The video demonstrates running Claude on a remote machine.
Does Rex keep Claude Code running when I close my laptop?
Rex is designed to keep programs attached to persistent sessions, even when its client disconnects. The video demonstrates Claude continuing on a remote machine while the laptop is closed.