A curated list of awesome resources for WebExtensions development.

WebExtensions are a cross-browser system for developing browser add-ons. To a large extent the system is compatible with the extension API supported by Google Chrome and Opera. Extensions written for these browsers will in most cases run in Firefox or Microsoft Edge with just a few changes.

• Getting started
• Community
• Libraries and Frameworks
• Tools
• Testing
• Boilerplates
• Sample Extensions

• Chrome Extensions documentation - Documentation for the original Chrome extension model.
• Chrome Extensions API - Comprehensive documentation on the original API provided by Chrome.
• Mozilla's WebExtensions documentation - MDN wiki for the WebExtensions API.
• Browser support for WebExtensions - Compatibility table for Chrome, Edge, Firefox, and Opera.
• Microsoft Edge API support - Detailed WebExtensions support for Edge.
• Safari Extensions documentation - Developer documentation on building Safari extensions. Technically not WebExtensions, the API is completely different.
• Opera API support - Detailed WebExtensions support for Opera.
• Porting Chrome Extensions to Firefox - Guide to prepare, install, and debug Chrome extensions to be ported in Firefox.
• Browser Extension Standard - Standard for the API, supported by Mozilla, Opera and Microsoft.

• Google Groups - Discussions.
• Mozilla Discourse - Discussions.
• #webextensions - IRC channel by Mozilla.
• google-chrome-extension tag on Stack Overflow - Relevant questions.
• firefox-webextensions tag on Stack Overflow - Relevant questions.
• microsoft-edge-extension tag on Stack Overflow - Relevant questions.

Code meant become part of the extension.

• webext-options-sync - Helps you manage and autosave your extension's options.
• webext-storage-cache - Map-like promised cache storage with expiration.
• webext-dynamic-content-scripts - Automatically inject your content_scripts on custom domains.
• mozilla/webextension-polyfill - Polyfill to support the standardized promise based API in the browser namespace.
• redux-webext - Uses redux for managing the state of your WebExtension.

Apps that help you manage your extensions.

• Chrome Webstore Upload - Upload the extension to the Chrome Web Store via cli (or on Travis, automatically).
• mozilla/web-ext - Command line tool to help build, run, and test WebExtensions.
• chromepet - Get notified when your new version has been published.
• chrome-ext-downloader - Download any extension on Chrome Web Store to see how they do it.
• chrome-store-api - Chrome Web Store API wrapper.
• Chrome extension source viewer - WebExtension to view source code of extensions directly on the store.
• @wext/shipit - Tool to automatically publish to Chrome Web Store, Mozilla Addons and Opera Addons.
• web-ext-translator - Translator tool to manage i18n messages.json.
• cwex - A CLI tool for creating and managing cross-platform browser extensions.

• sinon-chrome - Mocks the Chrome Extensions API for testing.
• addons-validator - Validate an extension against Mozilla's guidelines.

• browser-extension-template - Barebones boilerplate with webpack, options handler and auto-publishing.
• create-webextension - Yarn WebExtension generator.
• extensionizr.com - Web UI that helps you create an initial configuration and files.
• generator-web-extension - WebExtension generator that creates everything you need to get started with cross-browser web-extension development.

These are simple and modern WebExtensions repositories that could help you figure out where pieces go, including automatic deployment via Travis CI.

• npmhub
• Hide Files on GitHub
• mdn/webextension-examples - Various example extensions curated for the MDN documentation.

To the extent possible under law, Federico Brigante has waived all copyright and related or neighboring rights to this work.