scripts/userscripts/pixiv-ai-notifier.user.js

// ==UserScript==
// @name        AI notifier for Pixiv
// @description Notify you when an AI artwork is detected (through tags) on Pixiv
// @namespace   tretrauit-dev
// @match       *://www.pixiv.net/*
// @icon        https://upload.wikimedia.org/wikipedia/commons/7/7e/Pixiv_Icon.svg
// @grant       none
// @version     1.0.2
// @author      tretrauit
// @run-at      document-idle
// @homepageURL https://gitlab.com/tretrauit/scripts
// @supportURL  https://gitlab.com/tretrauit/scripts/-/issues
// @downloadURL https://git.tretrauit.me/tretrauit/scripts/raw/branch/main/userscripts/pixiv-ai-notifier.user.js
// ==/UserScript==

function checkAI() {
    if (!window.location.pathname.includes("/artworks/")) {
        return;
    }
    const tagElms = document.querySelectorAll(".gtm-new-work-tag-event-click");
    for (const elm of tagElms) {
        if (elm.parentElement.parentElement.textContent.toLowerCase().includes("ai")) {
            alert("AI artwork detected :(");
            break;
        }
    }
}

// Stack Overflow thingy
let previousUrl = "";

const observer = new MutationObserver(() => {
  if (window.location.href !== previousUrl) {
    console.log(`URL changed from ${previousUrl} to ${window.location.href}`);
    previousUrl = window.location.href;
    // do your thing
    setTimeout(checkAI, 1000);
  }
});
const config = { subtree: true, childList: true };

// start observing change
console.log("AI notifier for Pixiv is running...");
observer.observe(document, config);
setTimeout(checkAI, 1000);