Introducing rmux: An Open‑Source API‑Driven Terminal Multiplexer for AI Agents

What rmux Is

rmux is a terminal multiplexer with an API, written from scratch in Rust. It implements more than 90 tmux commands, keeping the familiar tmux workflow while exposing typed SDKs for Rust ( rmux-sdk), Python ( librmux) and TypeScript ( @rmux/sdk) that let programs drive a terminal like Playwright drives a browser.

Feature Details

Compatibility Layer

rmux does not reinvent tmux commands; it directly re‑exports the most common ones such as new-session, split-window, send-keys, and attach-session. Compatibility tests ensure the command set works as expected, so existing muscle memory is preserved.

When a dedicated rmux configuration is missing, rmux falls back to parsing the user's existing tmux.conf. Unsupported plugins are reported without crashing.

Scripting: Playwright‑Style Terminal SDKs

The SDK connects to a local rmux daemon and exposes session, pane, stream, wait, and snapshot interfaces. Code can create sessions, send text to panes, wait for specific output, and capture screen snapshots without using sleep or manual string parsing.

Cross‑Platform Support

Unlike tmux, which relies on WSL for Windows, rmux uses Rust’s native IPC: Unix sockets on Linux/macOS and Named Pipes on Windows, delivering a true native experience on all three OSes.

Web Share

rmux can stream a single pane or an entire session to a browser via an end‑to‑end encrypted WebSocket. Execution stays on the local machine; the browser only renders the stream. Both loopback preview and tunnel‑based exposure are supported, using hybrid post‑quantum encryption.

Ratatui Integration

For Rust TUI applications, rmux provides the ratatui-rmux widget, allowing live pane snapshots to be rendered directly inside a Ratatui buffer, giving a true embedded terminal pane.

Claude Teammate Mode

The built‑in rmux claude command adds --teammate-mode tmux when running Claude Code, inserting a private tmux shim into Claude’s PATH without affecting the system tmux.

Quick Start

Installation options include a one‑click script for macOS/Linux, PowerShell for Windows, Homebrew, and Cargo:

curl -fsSL https://rmux.io/install.sh | sh

irm https://rmux.io/install.ps1 | iex

brew install rmux

cargo install rmux --locked

After installation, list supported commands and run a simple workflow:

rmux list-commands
rmux new-session -d -s work
rmux split-window -h -t work
rmux send-keys -t work 'echo "hello from rmux"' Enter
rmux attach-session -t work

To drive rmux from Rust, add dependencies:

cargo add rmux-sdk
cargo add ratatui-rmux

Python and TypeScript SDKs are available as librmux and @rmux/sdk respectively.

Author's Opinion

rmux is still evolving rapidly, so bugs are expected and heavy tmux‑plugin users should not expect a seamless migration yet. Nevertheless, the API‑first design aligns with the broader trend of treating terminal control as a programmable interface, similar to how Playwright solved browser automation. The author, being an agent user himself, built rmux to solve daily pain points, and finds the wait_for_text API far more comfortable than tmux’s expect scripts.

GitHub repository:

https://github.com/Helvesec/rmux