Userscript: AI Studio Auto-Fill & Collapse System Instructions

// ==UserScript==
// @name         AI Studio: Auto-Fill & Collapse on New Chat
// @author       Alan Dias (c)2025
// @version      1.4
// @description  Whenever you open or switch to a new Chat in Google AI Studio, this script auto-clicks “System instructions,”
 //              injects your saved prompt text, then collapses the panel again.
// @match        https://aistudio.google.com/*
// @grant        none
// ==/UserScript==

(function () {
    'use strict';

    // ────────────────────────────────────────────────────────────────────────────
    // 👇 Edit this constant to whatever “System Instructions” text you want:
    const SYSTEM_INSTRUCTIONS = `
You are a top‐tier, elite programmer.Provide a precise short answer only.
`.trim();
    // ────────────────────────────────────────────────────────────────────────────

    // How often (ms) to retry internally when waiting for textarea to appear
    const CHECK_INTERVAL_MS = 200;
    // Maximum number of retries when injecting per attempt
    const MAX_INNER_ATTEMPTS = 20;

    // Internal flag to prevent overlapping jobs
    let injectionInProgress = false;

    /**
     * Attempts to open the System Instructions panel, inject text, then collapse it.
     * Returns immediately if another injection is in progress, or if the textarea already
     * contains the exact SYSTEM_INSTRUCTIONS.
     */
    function openInjectCollapse() {
        if (injectionInProgress) {
            return;
        }
        injectionInProgress = true;

        // 1) Find the “System instructions” button by its aria-label
        const toggleButton = document.querySelector('button[aria-label="System instructions"]');
        if (!toggleButton) {
            // If button is not found, bail out and allow MutationObserver to try again later.
            injectionInProgress = false;
            return;
        }

        // 2) Click to open the panel
        toggleButton.click();
        console.log('[Userscript] ▶ Opened System Instructions panel.');

        // 3) Now wait until the textarea appears, up to MAX_INNER_ATTEMPTS times
        let innerAttempts = 0;
        const innerInterval = setInterval(() => {
            innerAttempts++;
            // a) Look for the <textarea aria-label="System instructions">
            const textarea = document.querySelector('textarea[aria-label="System instructions"]');
            if (textarea) {
                // b) If its value is already exactly our instructions, skip reinjection
                if (textarea.value.trim() !== SYSTEM_INSTRUCTIONS) {
                    textarea.value = SYSTEM_INSTRUCTIONS;
                    // Fire an input event so AI Studio notices the change
                    textarea.dispatchEvent(new Event('input', { bubbles: true }));
                    console.log('[Userscript] ✅ Injected new System Instructions.');
                } else {
                    console.log('[Userscript] ☑ Text already present; skipping injection.');
                }

                // c) Wait a tiny bit so Angular can register the change, then collapse
                setTimeout(() => {
                    toggleButton.click();
                    console.log('[Userscript] ⏬ Collapsed System Instructions panel.');
                    clearInterval(innerInterval);
                    injectionInProgress = false;
                }, 150);
                return;
            }

            // d) If we've retried too many times, give up and reset
            if (innerAttempts >= MAX_INNER_ATTEMPTS) {
                console.warn('[Userscript] ⚠️ Gave up waiting for textarea.');
                clearInterval(innerInterval);
                injectionInProgress = false;
            }
        }, CHECK_INTERVAL_MS);
    }

    // ────────────────────────────────────────────────────────────────────────────
    // 1) Run once on script load (in case you landed directly on a Chat page)
    openInjectCollapse();

    // 2) Observe DOM mutations so that, when AI Studio does a client-side “New Chat”
    //    (or any re-render) we automatically run `openInjectCollapse()` again.
    const observer = new MutationObserver((mutations) => {
        for (const m of mutations) {
            // If a new “System instructions” button node appears, trigger injection.
            // We check addedNodes for any element matching our button selector.
            for (const node of m.addedNodes) {
                if (!(node instanceof HTMLElement)) continue;
                // If this exact node or any child of it matches the button, invoke
                if (node.matches?.('button[aria-label="System instructions"]') ||
                    node.querySelector?.('button[aria-label="System instructions"]')) {
                    openInjectCollapse();
                    return;
                }
            }
        }
    });

    // Start observing the entire <body> for subtree modifications:
    observer.observe(document.body, {
        childList: true,
        subtree: true
    });
    // ────────────────────────────────────────────────────────────────────────────

})();