Sticky Model

A zero-UI Chrome extension that persists your Gemini model choice across new chats.

When you select a model (e.g. "Pro") on gemini.google.com, Gemini resets it back to the default every time you start a new chat. This extension remembers your last explicit choice and automatically restores it.

No popup, no options page, no menu. It just works.

Install (local / developer mode)

1. Clone or download this repository.
2. Open Chrome and navigate to chrome://extensions.
3. Enable Developer mode (toggle in the top-right corner).
4. Click Load unpacked and select the repository folder.
5. Navigate to gemini.google.com — the extension is now active.

How it works

• A content script (content.js) runs on gemini.google.com.
• It detects the model selector chip and watches for changes.
• When you explicitly pick a model, it saves your choice to chrome.storage.local.
• On page load or SPA navigation (new chat), it checks the selector and restores your saved preference if the model has been reset.
• A MutationObserver and pushState/replaceState patches detect SPA navigations without full page reloads.

Development

Prerequisites

• Node.js 18+
• Yarn (the repo uses Yarn 4 via Corepack)

Install dependencies

corepack enable
yarn install

Run E2E tests

yarn test:e2e

On the first run, a Chrome window will open. Log in to your Google account when prompted. The session is saved in tests/.chrome-profile/ so you only need to authenticate once.

Run all tests

yarn test

Project structure

manifest.json      Chrome extension manifest (Manifest V3)
content.js         Content script — model detection, storage, and restoration
background.js      Minimal service worker — exposes chrome.storage for tests
package.json       Dev dependencies (Vitest, Playwright)
tests/
  e2e/
    extension.test.js   E2E tests against real gemini.google.com
  helpers/
    setup.js            Playwright browser launch + auth-wait helper

License

MIT