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All of @webext-core's packages are provided via NPM. Depending on your project's setup, you can consume them in 2 different ways:

  1. If your project uses a bundler like Vite or Webpack, see Bundler Setup.
  2. If your project does not use a bundler, see Non-bundler Setup

List of packages

Bundler Setup

If you haven't setup a bundler yet, I recommend using vite and vite-plugin-web-extension for the best DX and to support all browsers.

# Bootstrap a new project
pnpm create vite-plugin-web-extnesion

Install any of the packages and use them normally. Everything will just work 👍

pnpm i @webext-core/storage
import { localExtStorage } from '@webext-core/storage';

const value = await localExtStorage.getItem('some-key');

Non-bundler Setup

If you're not using a bundler, you'll have to download each package and put it inside your project.

Why download them?

With Manifest V3, Google doesn't approve of extensions using CDN URLs directly, considering it "remotely hosted code" and a security risk. So you will need to download each package and ship them with your extension. See the MV3 overview for more details.

If you're not on MV3 yet, you could use the CDN, but it's still recommended to download it so it loads faster.

All of @webext-core NPM packages include a minified, lib/ file that will create a global variable you can use to access the package's APIs.

Lets say you've put all your third-party JS files inside a vendor/ directory, and want to install the @webext-core/storage package.

├─ vendor
│  └─ jquery.min.js
└─ manifest.json

You can download the package like so:

mkdir -p vendor/webext-core
curl -o vendor/webext-core/storage.js

You project should now look like this:

├─ vendor
│  ├─ jquery.min.js
│  └─ webext-core
│     └─ storage.js
└─ manifest.json

Now you can include the vendor/webext-core/storage.js file in your extension! Each package sets up it's own global variable, so refer to the individual docs for that variable's name. In this case, it's webExtCoreStorage.

HTML Files
  <script src="/vendor/webext-core/storage.js"></script>
    const { localExtStorage } = webExtCoreStorage;

    const value = await localExtStorage.getItem('some-key');
Content Scripts
"content_scripts": [{
  "matches": [...],
  "js": ["vendor/webext-core/storage.js", "your-content-script.js"]
MV2 Background
"background": {
  "scripts": ["vendor/webext-core/storage.js", "your-background-script.js"]
MV3 Background

For MV3 background scripts, you need to use a bundler since background.service_worker only accepts a single script.

Released under the MIT License.