Building a Chrome Extension with Antigravity: A Step-by-Step Guide

Building Chrome Extensions used to be a pain. Manifest files, content scripts, background workers, popup HTML… it's a lot of boilerplate.

With Google Antigravity, you can build one in 5 minutes.

In this tutorial, we will build a “Focus Mode” extension that blocks distracting websites.

Step 1: The Prompt

Open Antigravity and type this into the Chat:

> “Create a Chrome Extension called ‘Focus Mode'.
> Features:
> 1. A popup with a big ‘Focus' button.
> 2. When clicked, it blocks ‘youtube.com' and ‘twitter.com'.
> 3. Use Manifest V3.
> 4. Make the popup look modern and dark mode.”

Step 2: The Artifact

Antigravity will generate an Artifact containing the file structure:
* `manifest.json`
* `popup.html`
* `popup.css`
* `popup.js`
* `background.js`

It will show you a Preview of the popup UI directly in the Artifact window. You can click the button to test the UI logic.

Step 3: Refinement

You notice the button is blue, but you want it red.
> “Make the Focus button red and add a ‘Stop' button.”

The Artifact updates instantly.

Step 4: Testing in Integrated Browser

This is the magic part. You don't need to load the extension into your real Chrome browser yet.

1. Open the Integrated Browser in Antigravity.
2. Click the “Extensions” icon in the browser toolbar.
3. Select “Load Unpacked” -> Point to your workspace.
4. Navigate to `youtube.com`.
5. Click your extension icon and hit “Focus”.
6. Watch YouTube get blocked.

Step 5: Publishing

Once it works, ask Antigravity:
> “Package this extension for the Chrome Web Store.”

It will:
1. Zip the files.
2. Generate the necessary icons (16×16, 48×48, 128×128) using its image generation capabilities.
3. Write a `README.md` for your submission.

Conclusion

Antigravity turns the complex process of extension development into a conversation. You focus on the idea, and the IDE handles the plumbing.

At BYS Marketing, we build custom browser extensions for clients to automate internal workflows, all built with Antigravity.

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Have an idea for a browser extension?
Contact BYS Marketing. We can build it for you in record time.