mushroom11s/Tailcat-Box

Private, peer-to-peer connections between your computers. No account, no server to run, no port forwarding.

English | 简体中文

Tailcat Box (猫砂盆) is a desktop app for Windows, macOS, and Linux that connects two computers directly, wherever they are. Open the app, share a short tc… address or code, and you can talk, send files, reach each other's services, or open a remote shell, all from one window.

It is built on Tailscale Tailcat: connections are brokered through public DERP relays and switch to a direct path when the network allows, so neither side needs a public IP, router configuration, or an account. Tailcat Box is for developers, IT helpers, and small teams who want a quick, private link between machines without setting up a VPN or relying on a cloud service to hold their files.

• Reach your home or office network from anywhere: publish a NAS dashboard, an admin page, or a dev server on a Tailcat address and open it from another network, with no public IP or router port forwarding.
• Show a work-in-progress site to colleagues or clients: share your dev server's port and send the address; several people can connect at the same time through their own Tailcat Box while you keep coding.
• Send large files directly, without a cloud drive: drop files into Mew Share and send the pickup code to one or more people, who download straight from your computer with no upload step or third-party storage.
• Help a family member or coworker remotely: talk on a voice or video call, have them share their screen, and, if they allow it, open a shell on their machine over SSH to fix the problem.
• Keep a private conversation between two machines: chat, voice notes, and calls travel between the two Tailcat Box apps through Tailcat, with no chat service account involved.
• Expose a device on your LAN to someone remote: forward the web interface of a printer, IP camera, router, or embedded board on your local network so remote peers, several at once if needed, can reach it through your computer.

One-to-one rooms for text, files, and voice notes, with voice and video calls and screen sharing built in.

• Connect by pasting an address or scanning a QR code
• Keep several rooms open and switch between them
• Open a shared screen in its own window at full resolution

Text, voice notes, and call records

Video calls stay next to the conversation

Shared screen, expandable to full resolution

Peer-to-peer file sharing with a pickup code or QR code.

• One pickup code can be used by several recipients, up to the download limit you set (up to 10 download at the same time; others wait in line)
• Run several shares at once, each with its own expiry
• Large shares are served from their original location instead of being copied
• Shares resume with the same code after the app restarts

Make TCP services reachable across networks, in either direction. One address can be shared with many people, and they can all connect at the same time.

• Publish ports on this machine, or on another host in your LAN (8080:192.168.1.10:80)
• Forward a peer's port to your own machine, or open their web page directly
• Use a saved key to keep the same address across restarts

A built-in shell served by Tailcat, separate from the operating system's sshd.

• Off by default; only saved devices and current chat peers are allowed in
• Open sessions in the in-app terminal or your system terminal

• Native builds for Windows, macOS, and Linux on x64 and ARM64
• Runs in the system tray, so rooms, shares, and tunnels keep working when the window is closed
• English and Simplified Chinese, light and dark themes, in-app updates

Preparing a share	Pickup code and QR code
Download in progress	Scan from the camera, an image, or the clipboard

Download the latest version from GitHub Releases.

Linux builds require glibc 2.39 or later (Ubuntu 24.04+, Debian 13+, Fedora 40+). Release builds are not code-signed, so Windows SmartScreen and macOS Gatekeeper will ask for confirmation on first launch. See the user guide for installation details.

1. Install Tailcat Box on both computers.
2. Chat: create a room on one side and send its address; the other side pastes or scans it and connects.
3. Files: drop files into Mew Share and send the pickup code; the recipient enters it under Download.
4. Services: in Tunnel, add a Port serve mapping (for example 8080) and send the address; the peer adds a Local forward to it.

• User guide: features in detail, configuration, data locations, troubleshooting, and Linux notes
• FAQ: rooms, temporary addresses, nicknames, and remarks
• Release notes: changes in each version

Requirements: Go 1.27.1+, Node.js 20.19+ (or 22.12+), and Wails CLI v2.16.0, plus the platform webview toolchain (libgtk-3-dev and libwebkit2gtk-4.1-dev on Linux).

git clone https://github.com/mushroom11s/tailcat-box.git
cd tailcat-box
wails dev                          # run in development mode
wails build                        # build into build/bin/
go test ./...                      # run tests

On Linux, add -tags webkit2_41. Set TAILCAT_ADAPTER=fake to develop offline. Packaging and releases are covered in docs/releases/README.md.

Issues and pull requests are welcome. Please describe your OS, architecture, and app version when reporting a bug, target main with focused pull requests, and update both frontend/src/i18n/en.ts and zh-CN.ts when changing UI text.

Anyone who has a room address, Tunnel address, or pickup code can connect to it, so share them only with people you trust and stop them when you are done. Transport security is provided by Tailcat, which encrypts tunnel traffic with WireGuard; see its documentation for details. Release binaries are unsigned; download them only from this repository.

To report a vulnerability, please do not post details publicly. Open an issue asking for a private contact channel and the maintainer will follow up.

Tailcat Box is licensed under the PolyForm Noncommercial License 1.0.0. Commercial use requires a separate license from the copyright holder. Third-party components, including github.com/tailscale/tailcat, remain under their own licenses.

Tailcat Box is built on Tailcat and Tailscale, with Wails, React, and WebKitGTK.