The @trezor/connect-webextension package provides an implementation of @trezor/connect designed specifically for MV3 web extensions. Key features include:

• Compatibility with service worker environments.
• Full access to the TrezorConnect API.
• Popup-based user interaction through Suite Web.
• Response delivery back to the calling service worker.

Architecture

This package exclusively uses the externally_connectable API. It does not inject connect-script, does not use inline iframes as in the previous @trezor/connect versions.

The flow is:

1. The service worker checks for suite-desktop app. If running, it opens a websocket connection to it. If not, it opens Suite Web in a browser.
2. The user handles their request inside the dedicated Trezor UI
3. Response is returned to your application

Setup

1) manifest.json

Allow Suite Web origins to message your extension using externally_connectable. Without this, the Suite Web flow would not be available.

"externally_connectable": {
  "matches": [
    "https://suite.trezor.io/*"
  ]
}

2) Service worker

Import the library in your service worker (MV3 background):

import TrezorConnect from '@trezor/connect-webextension';

The library is available in the service worker context. If you need to call it from your extension UI, communicate with the service worker using your own messaging layer.

Note: the service worker may be suspended when idle, so you should wake it up before invoking TrezorConnect.