Guacamole Clipboard Bridge Autor: Nara

Native copy & paste for the CyberArk PAM HTML5 Gateway - in Firefox.

The CyberArk PAM HTML5 Gateway (built on Apache Guacamole) supports clipboard synchronization in Chromium-based browsers, but not in Firefox. This is because Firefox does not implement the clipboard-read permission of the asynchronous Clipboard API for web pages, so copy & paste inside remote RDP sessions silently fails. This extension exists specifically to fix that.

Features

• Paste into the session - Ctrl+V sends your local clipboard to the remote desktop.
• Copy from the session - text you copy in the remote desktop lands in your local clipboard automatically.
• Works in both directions using the normal keyboard shortcuts.
• Handles large text safely by chunking it, so it never exceeds the gateway's frame limit.
• Full UTF-8 support - umlauts, accents, and emoji are preserved.
• Domain-restricted: the extension only activates on the gateway domains you configure, and stays completely passive everywhere else.
• Automatically dismisses the gateway's "native copy-paste not supported" warning.

Privacy

This extension collects no data. Clipboard contents are sent only to your active remote session - never logged, stored, or transmitted anywhere else. It runs only on the domains you explicitly add in the settings.

Setup

After installing, open the extension's options and add your gateway domain (for example, gateway.example.com). Then reload your gateway tab. A status indicator in the toolbar popup shows when the connection has been detected.

Requirements

Firefox 140 or newer, and a CyberArk PAM HTML5 Gateway served over HTTPS. Because the gateway is built on Apache Guacamole, other Guacamole-based HTML5 gateways may also work, but CyberArk PAM is the tested target.

Limitations

Text only - images and files are not transferred (use the gateway's own file-transfer feature for those).

This is an independent, unofficial project. It is not affiliated with, endorsed by, or associated with CyberArk Software Ltd. or any other vendor. "CyberArk" is used only to describe the product this extension is compatible with.