Chrome Extensions with Flutter

Two Chrome extensions built with Flutter web, both on Manifest V3.

• example1 is the smallest possible starter: the default Flutter counter app running inside an extension popup.
• bitcoin_tracker is Crypto Tracker: live prices, logos and 24h change for the top 100 coins, pulled from the CoinPaprika API. No API key needed.

Build

Chrome does not allow eval inside extensions, so build with the CSP flag:

cd bitcoin_tracker
flutter build web --csp

Install

1. Open chrome://extensions
2. Turn on Developer mode
3. Click Load unpacked and select the build/web folder

How it works

Flutter compiles the app to plain web assets, and the extension is defined by web/manifest.json. The popup size comes from the inline style on the html tag in web/index.html (350x650 here, Chrome caps popups at 800x600).