Raising an issue to implement clipboard() helper function, since this may be something commonly used. In normal user workflows, it would be using keyboard [ctrl]c and keyboard [ctrl]v (or [cmd] for macOS) to copy and paste text from the clipboard.
However, in some situations, getting the value store in clipboard directly to a variable in TagUI for usage, or setting the clipboard directly from a variable in TagUI would be very helpful. For eg, select all and copy to clipboard a PDF document, and then using clipboard() to access the value for data extraction / string-parsing etc.