A template for creating cross-browser extensions

Usage no npm install needed!

<script type="module">
  import extensionBoilerplate from 'https://cdn.skypack.dev/extension-boilerplate';



Browser extensions for Band Chain

Similarly to MetaMask, BandMask allows developers to build dApp UI on website. It exposes instance of Band Protocol Client to the web, and allows the dApp to communicate with blockchain without having to manage user wallet credentials itself.

I have extracted this from the browser extensions that I built for my side-project, Email This.

Side note: Do check out Email This. It is a simpler alternative to bookmarking tools like Pocket, Readability & Instapaper. Email This will remove ads & distractions from an article and send you a nice email with just the text/images. No need to install any additional applications or login to another app just to access your bookmarks. The Chrome Extensions is available on the Chrome Web Store.


Write once and deploy to Chrome, Opera & Firefox
Based on WebExtensions. It also includes a tiny polyfill to bring uniformity to the APIs exposed by different browsers.
Your changes to CSS, HTML & JS files will be relayed instantly without having to manually reload the extension. This ends up saving a lot of time and improving the developer experience.
Sensible starting point
This comes with a gulp based workflow that converts modern ES6 JavaScript and SCSS to JS/CSS. Scripts are transpiled using Babel and bundled using Browserify. Sourcemaps are available for both JS and SCSS.
Sketch (.sketch) assets for icons and promo images
A .sketch file is included in the resources directory. This has all the icons and promo images that will be needed while uploading the extensions to the app stores.
Easily configurable and extendable
The gulpfile is easily understandable and configurable. If you want to add additional tasks or remove un-used ones, you can easily tweak that file to suit your needs.
Platform specific & Environment specific variables.
You might need to specify different data variables based on your environment. For example, you might want to use a localhost API endpoint during development and a production API endpoint once the extension is submitted to the appstore. You can specify such data in the json files inside `config` directory.
You can also set custom data variables based on the platform (different variable for Chrome, FF, Opera).


gt; yarn install
gt; yarn build

Alternately, if you want to try out the sample extension, here are the download links. After you download it, unzip the file and load it in your browser using the steps mentioned below.

Load the extension in Chrome & Opera
  1. Open Chrome/Opera browser and navigate to chrome://extensions
  2. Select "Developer Mode" and then click "Load unpacked extension..."
  3. From the file browser, choose to extension-boilerplate/build/chrome or (extension-boilerplate/build/opera)
Load the extension in Firefox
  1. Open Firefox browser and navigate to about:debugging
  2. Click "Load Temporary Add-on" and from the file browser, choose extension-boilerplate/build/firefox


The following tasks can be used when you want to start developing the extension and want to enable live reload -

  • npm run chrome-watch
  • npm run opera-watch
  • npm run firefox-watch


Run npm run dist to create a zipped, production-ready extension for each browser. You can then upload that to the appstore.


  • Add support for Safari
  • Add Firefox & Opera Promo images
  • Add sample screenshot templates
  • Write a guide for using config variables & JS preprocessor

This project is licensed under the MIT license.

If you have any questions or comments, please create a new issue. I'd be happy to hear your thoughts.

Bharani, Email This