wong2 kim

Posted on May 18

Native Windows Terminal for AI coding agents — no WSL

#ai #productivity #terminal #windows

Native Windows terminal for AI coding agents — no WSL

wmux is a native Windows terminal multiplexer for running Claude Code, Codex CLI, and Gemini CLI side-by-side. Split panes, MCP auto-registration, built-in browser with full CDP automation, and session persistence that survives reboot. MIT.

winget install openwong2kim.wmux

GitHub: https://github.com/openwong2kim/wmux

The problem

Run multiple AI coding agents in parallel on Windows and your options are bleak:

WSL + tmux: breaks native clipboard, taskbar, and file paths.
Multiple Terminal windows: no shared layout, no persistence.
VSCode terminal: not a real multiplexer.

cmux exists for macOS. Nothing existed for Windows. So I built wmux.

What it does

Split panes, ConPTY-native

Ctrl+D splits right, Ctrl+Shift+D splits down. Pure ConPTY underneath — the same pseudo-terminal API behind Windows Terminal. xterm.js + WebGL rendering. 999K-line scrollback persisted to disk.

Tmux-style prefix mode (Ctrl+B then an action key) is built in — 13 default actions, all rebindable.

Your agent can drive a real browser

wmux ships a built-in browser panel connected via Chrome DevTools Protocol. When Claude Code runs in a pane, an MCP server auto-registers itself in ~/.claude.json. You can say:

"Search Google for wmux and screenshot the top result"

…and Claude actually does it:

browser_open
  → browser_navigate("https://google.com")
  → browser_fill(ref=13, "wmux")
  → browser_press_key("Enter")
  → browser_screenshot()

Works with React controlled inputs (CDP keystrokes, not just value=) and CJK text. No puppeteer.launch() boilerplate — the browser is already there.

Session persistence that survives reboot

A separate daemon owns the PTYs. Close the app — the daemon keeps them alive. Reopen — sessions reconnect, scrollback intact. Reboot — wmux auto-starts and restores state from disk via atomic .bak-rotated saves.

Output-throughput agent monitoring

You don't know when a long-running agent is done. wmux watches output throughput, not specific strings. When the agent goes quiet after being noisy, you get a taskbar flash + Windows toast. Works with any agent.

It also flags dangerous commands before they run: git push --force, rm -rf, DROP TABLE.

Security

Token-authenticated Named Pipes for all IPC
SSRF guard on browser navigate — blocks 127.0.0.1, file://, javascript:
PTY input sanitization
Randomized CDP port per session
Memory watchdog reaps dead sessions at 750MB
Electron Fuses: RunAsNode off, cookie encryption on

Install

winget install openwong2kim.wmux
# or
choco install wmux

Open Claude Code in any pane — MCP registers automatically. No config to write.

GitHub: https://github.com/openwong2kim/wmux (v2.9.1, MIT)

Feedback and stars welcome.

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