Copy/Paste for noVNC Proxmox

noVNCCopyPasteProxmox.user.js

// ==UserScript==
// @name         noVNC Paste for Proxmox
// @namespace    http://tampermonkey.net/
// @version      0.2a
// @description  Pastes text into a noVNC window (for use with Proxmox specifically)
// @author       Chester Enright
// @match        https://*
// @include      /^.*novnc.*/
// @require http://code.jquery.com/jquery-3.3.1.min.js
// @grant        none
// ==/UserScript==
const delay = 1
;(function () {
    'use strict'
    window.sendString = function(text) {

        var el = document.getElementById("canvas-id")
        text.split("").forEach(x=>{
            setTimeout(()=>{
                 var needs_shift = x.match(/[A-Z!@#$%^&*()_+{}:\"<>?~|]/)
                 let evt
                 if (needs_shift) {

                     evt = new KeyboardEvent("keydown", {keyCode: 16})
                     el.dispatchEvent(evt)
                     evt = new KeyboardEvent("keydown", {key: x, shiftKey: true})
                     el.dispatchEvent(evt)
                     evt = new KeyboardEvent("keyup", {keyCode: 16})
                     el.dispatchEvent(evt)

                 }else{
                     evt = new KeyboardEvent("keydown", {key: x})
                }
                el.dispatchEvent(evt)
            }, delay)
        })

    }


    $(document).ready(function() {
        setTimeout(()=>{
            console.log("Starting up noVNC Copy/Paste (for Proxmox)")

            $("canvas").attr("id", "canvas-id")

            $("canvas").on("mousedown", (e)=>{
                if(e.button == 2){ // Right Click
                    navigator.clipboard.readText().then(text =>{
                        window.sendString(text)
                    })
                }
            })
        }, 1000);
    })


})()

For some reason the "|" symbol wasn't pasting properly for me, so I did this:

// ==UserScript==
// @name         noVNC Paste for Proxmox
// @namespace    http://tampermonkey.net/
// @version      0.2a
// @description  Pastes text into a noVNC window (for use with Proxmox specifically)
// @author       Chester Enright
// @match        https://*
// @include      /^.*novnc.*/
// @require http://code.jquery.com/jquery-3.3.1.min.js
// @grant        none
// ==/UserScript==
const delay = 1
;(function () {
    'use strict'
    window.sendString = function(text) {

        var el = document.getElementById("canvas-id")
        text.split("").forEach(x=>{
            setTimeout(()=>{
                var needs_shift = x.match(/[A-Z!@#$%^&*()_+{}:"<>?~|]/)
                 let evt
                 if (needs_shift) {
                     switch (x) {
                         case '|':
                             evt = new KeyboardEvent("keydown", {which: 16, keyCode: 16, shiftKey: true, key: "Shift"})
                             el.dispatchEvent(evt)
                             evt = new KeyboardEvent("keydown", {which: 220, keyCode: 220, shiftKey: true, key: "|"})
                             el.dispatchEvent(evt)
                             evt = new KeyboardEvent("keyup", {which: 16, keyCode: 16, shiftKey: false, key: "Shift"})
                             el.dispatchEvent(evt)
                             break;
                         default:
                             evt = new KeyboardEvent("keydown", {which: 16, keyCode: 16, shiftKey: true, key: "Shift"})
                             el.dispatchEvent(evt)
                             evt = new KeyboardEvent("keydown", {shiftKey: true, key: x})
                             el.dispatchEvent(evt)
                             evt = new KeyboardEvent("keyup", {which: 16, keyCode: 16, shiftKey: false, key: "Shift"})
                             el.dispatchEvent(evt)
                             break;
                     }
                     /**/

                 }else{
                     evt = new KeyboardEvent("keydown", {key: x})
                     el.dispatchEvent(evt)
                     evt = new KeyboardEvent("keyup", {key: x})
                     el.dispatchEvent(evt)
                }
            }, delay)
        })

    }


    $(document).ready(function() {
        setTimeout(()=>{
            console.log("Starting up noVNC Copy/Paste (for Proxmox)")

            $("canvas").attr("id", "canvas-id")

            $("canvas").on("mousedown", (e)=>{
                if(e.button == 2){ // Right Click
                    navigator.clipboard.readText().then(text =>{
                        window.sendString(text)
                    })
                }
            })
        }, 1000);
    })


})()

I hope this would be helpful for somebody

Did some modifications (mostly with LLMs, yet tested massively and haven't found any bugs) to correctly work with new lines, symbols etc:

(function () {
    'use strict';

    let capsLockOn = false;
    const KEY_DELAY = 50;
    const SHIFT_NEEDED = /[A-Z!@#$%^&*()_+{}:"<>?~|]/;

    function simulateKeyEvent(el, eventType, key, options = {}) {
        const evt = new KeyboardEvent(eventType, { key, ...options });
        el.dispatchEvent(evt);
    }

    window.sendString = function(text) {
        const el = document.getElementById("novnc-canvas");
        if (!el) {
            console.error("Canvas element not found");
            return;
        }

        text.split('').forEach((char, index) => {
            setTimeout(() => {
                if (char === '\n') {
                    // Simulate "Enter" key press for line breaks
                    simulateKeyEvent(el, "keydown", "Enter");
                    simulateKeyEvent(el, "keyup", "Enter");
                } else {
                    const needsShift = SHIFT_NEEDED.test(char);
                    const isUpperCase = char >= 'A' && char <= 'Z';

                    if (needsShift) {
                        simulateKeyEvent(el, "keydown", "Shift", { keyCode: 16 });
                    }

                    if (isUpperCase && capsLockOn) {
                        simulateKeyEvent(el, "keydown", char.toLowerCase());
                        simulateKeyEvent(el, "keyup", char.toLowerCase());
                    } else {
                        simulateKeyEvent(el, "keydown", char);
                        simulateKeyEvent(el, "keyup", char);
                    }

                    if (needsShift) {
                        simulateKeyEvent(el, "keyup", "Shift", { keyCode: 16 });
                    }

                    if (char === "CapsLock") {
                        capsLockOn = !capsLockOn;
                        console.log("Caps Lock state changed:", capsLockOn);
                    }
                }
            }, index * KEY_DELAY);
        });
    };

    function waitForCanvas() {
        return new Promise((resolve) => {
            const checkCanvas = () => {
                const canvas = $("canvas");
                if (canvas.length > 0) {
                    canvas.attr("id", "novnc-canvas");
                    resolve(canvas);
                } else {
                    setTimeout(checkCanvas, 500);
                }
            };
            checkCanvas();
        });
    }

    async function setupNoVNCPaste() {
        try {
            console.log("Starting up noVNC Copy/Paste (for Proxmox) - Improved Version with Line Breaks");

            const canvas = await waitForCanvas();

            canvas.on("mousedown", (e) => {
                if (e.button == 2) { // Right Click
                    navigator.clipboard.readText()
                        .then(text => {
                            window.sendString(text);
                        })
                        .catch(err => {
                            console.error("Failed to read clipboard:", err);
                        });
                }
            });

            console.log("noVNC Copy/Paste setup completed");
        } catch (error) {
            console.error("Error setting up noVNC Copy/Paste:", error);
        }
    }

    $(document).ready(setupNoVNCPaste);
})();

Forked and updated it for German Mac Keyboard.
Added Async writing to be able to paste walls of text.

Tried many mapping variants, but mapping the whole keyboard worked best.

https://gist.github.com/JonasKrausch/3c64e4ca9f4a9bdde66a91759f24e574

it worked, thank you <3