WebExtensionTemplate

Create a browser extension for Chrome, Firefox and Safari in no time.

WebExtensionTemplate lets you skip the boilerplate and write a Web Extension with TypeScript and Svelte or React.

Features

• Popup window written in Svelte (or React) when you click the extension toolbar icon
• Extension settings page written in Svelte (or React)
• Lightning-fast build process to compile source code with esbuild
• Build scripts to package the extension for Chrome, Firefox and Safari
• Sourcemaps for local builds
• Minifies production builds
• iOS and macOS container apps written in SwiftUI for the Safari extension (no Swift / SwiftUI knowledge required to use)
• Prettier formatting
• webextension-polyfill to add a couple missing Promise-based APIs to Chrome

Future roadmap

• Separate branch with the popup and settings page written in React
• Tests

Setup

First, fork this repository. Then, follow the steps below. By the end of this, you should be able to search across the project for REPLACEME and get no results.

All browsers

• Update Extension/_locales/en/messages.json with an extension name and description
• Update Extension/README.md with your app's name
• Open Extension/package.json and update...
  • name with your app's name
  • author with your name
  • license with the app's license
• Open Extension/public/settings.html and update the <title> with your app's name
• Delete the <link> in Extension/settings.html if you don't like the provided CSS
• Create a toolbar icon for your app
  • Should be a small, simple glyph that makes sense when monochromatic in Safari
  • Make versions in 16, 19, 32, 38, 48 and 72-pixel sizes saved to Extension/images
  • Should be named toolbar_Qpx.png where Q is 16, 19, etc
• Make an app icon that is 1024 x 1024
  • Copy versions of it to Extension/images in 48, 96, 128, 256 and 512-pixel sizes
  • Should be named app_icon_Qpx.png , where Q is 48, 96, etc

Firefox

• Update manifest.json with a Firefox extension id (under gecko > id) in the format appname@domain.com

Safari

Do the following steps in Xcode.

Note: “Open the project config” means double-click the app name at the top of the file view in Xcode.

• Change the Safari app name to your app’s name
• Open Shared (App)/Models.swift and update APP_NAME with your app's name
• Create a new bundle identifier in the format com.domain.App-Name
  • Open the project config and go to AppName (iOS) > Signing & Capabilities and update the bundle id
  • Repeat for the macOS app
• Create a new bundle identifier. It should be your app bundle identifier with .Extension added onto the end. So if your app bundle ID is com.domain.App-Name, this should be com.domain.App-Name.Extension
  • Open the project config and go to AppName Extension (iOS) > Signing & Capabilities and update the bundle id with the extension bundle id
  • Repeat for the macOS extension
  • Update MAC_EXTENSION_BUNDLE_ID in Shared (App)/Models.swift with the extension bundle ID as well
• Update macOS (App)/AppDelegate.swift with a help documentation link
• Under project config > Signing & Capabilities, set the team for both apps and both extensions
• Under project config > General, update the display name for iOS and macOS
• Rename both files named REPLACEME.entitlements to be Your App Name.entitlements
  • Open the project config and to go to App Name (macOS) > Build Settings and find the setting for “Code Signing Entitlements.” Replace REPLACEME.entitlements with the name of your new entitlements file
  • Repeat for App Name Extension (macOS) > Build Settings > Code Signing Entitlements
• Open the project config and go to App Name Extension (macOS) > Build Settings and find the setting for “Bundle Display Name.” Update its value with your app’s name
  • Repeat for App Name Extension (iOS)
• Go to Product > Schemes > Manage Schemes… and update the iOS and macOS schemes with your app’s name
• iOS app icon:
  • Add the app icon to iOS (App)/iOS Assets as AppIcon with all the required sizes
  • Add a copy of the app icon named Icon.png in Shared (App)/Resources
• macOS app icon
  • Reduce the size of the app icon by 20% while keeping the canvas the same size
  • Add the app icon to macOS (App)/macOS Assets as with all the required sizes

Building your extension

All npm commands should be run in Extension. Safari extensions should be built in Xcode.

Browser	Local	Production
Chrome	npm run build	npm run build:chrome
Firefox	npm run build	npm run build:firefox
Safari	Product > Build	Product > Archive

• console.log calls are stripped out of prod builds
• The Chrome build script generates a zip that can be uploaded to the Chrome Web Store
• The Firefox build script generates a zip for the Mozilla Add-On Store as well as a zip of the source code for the store review

Other notes

• Firefox does not support service workers in the background, so I would maintain a separate branch firefox that runs dist/background.js as a background script