Download public browser extensions from official stores

extension-from-store

• Chrome Web Store, Microsoft Edge Add-ons, Firefox AMO
• Easy-to-use API
• Node.js + CLI support

Install

npm i extension-from-store

Usage

Designed for quiet reliability, extension-from-store keeps the interface simple and the output predictable.

Via Node.js:

import {fetchExtensionFromStore} from 'extension-from-store'

const url =
  'https://chromewebstore.google.com/detail/adblock-plus-free-ad-bloc/cfhdojbkjhnklbpkdaibdccddilifddb'

const options = {
  outDir: './extensions',
  userAgent: 'my-tool/1.0.0',
  extract: true,
  logger: {
    onInfo: (message) => console.log(message),
    onWarn: (message) => console.warn(message),
    onError: (message, error) => console.error(message, error)
  }
}

await fetchExtensionFromStore(url, options)

Via CLI (default command is fetch):

npx extension-from-store --url "<store-item-url>"
npx extension-from-store --url "<store-item-url>" --out ./my-exts
npx extension-from-store --url "<store-item-url>" --version 2.1.0 --extract
npx extension-from-store --url "<store-item-url>" --extract

The store is detected from the URL.

Output

<out>/
  <identifier>@<resolved-version>/
    extension.meta.json
    ...

If the target folder already exists, the operation fails.

By default, extension-from-store downloads the archive without extraction. When you pass --extract, it unpacks the archive and writes metadata.

When extraction is disabled, the archive is saved as:

<out>/<identifier>[@<version>].crx
<out>/<identifier>[@<version>].xpi

Extraction Rules

• .crx: strip CRX header, extract ZIP payload
• .xpi: treat as ZIP
• No normalization, no rewriting, no formatting

extension.meta.json

{
  "store": "chrome | edge | firefox",
  "identifier": "<identifier derived from the URL>",
  "version": "<resolved version>",
  "manifestVersion": 2 | 3
}

This file is written by extension-from-store to the same folder as the extracted files.

CLI Flags

| Flag | Required | Description | | --- | --- | --- | | --url <string> | Yes | Extension URL | | --out <path> | No | Output directory (default: ./extensions) | | --version <string> | No | Version hint | | --user-agent <string> | No | Override user agent | | --extract | No | Extract after download (default: download only) | | --quiet | No | Suppress info logs | | --verbose | No | Emit verbose info logs | | --json | No | JSON lines output to stdout |

Logging

Library logging is opt-in via the logger hooks. The library never writes directly to stdout/stderr.

Exit Codes

• 0 success
• 1 invalid input
• 2 unsupported store
• 3 not found / not public
• 4 download failed
• 5 extraction failed
• 6 filesystem conflict
• 7 store incompatibility

License

MIT (c) Cezar Augusto.