# About New WebExtensions API

## IRC: inforation from #maildev

11:21:30 : moz_mma : In Thunderbird 64.0a1, using ChromeUtils.import() in webextension results in "ReferenceError: ChromeUtils is not defined" error. Any pointers?
12:00:15 : &Fallen : moz_mma: unless you are in an WebExtensions Experiment context, ChromeUtils and all the chrome code is not available
you need to make due with the APIs available, and create wrappers for APIs that are missing
12:04:25 : moz_mma : Fallen, how do I get in WebExtensions Experiment context?
12:04:45 : &Fallen : moz_mma: https://github.com/thundernest/tb-web-ext-experiments/ explains it mostly
for the cloudfile experiment, you would have access in e.g. https://github.com/thundernest/tb-web-ext-experiments/blob/master/cloudfile/cloudfile-api/api.js but not https://github.com/thundernest/tb-web-ext-experiments/blob/master/cloudfile/background/background.js
please be sure to read the intro to that repo so you know what the APIs should look like
12:07:30 : moz_mma : Thanks Fallen
12:14:03 : +aceman : Fallen: the ChromeUtils question above

## Demo add-on

https://developer.mozilla.org/en-US/docs/Mozilla/Thunderbird/Thunderbird_extensions/Demo_Addon

## Utils in comm-central mailnews/base

https://github.com/mozilla/releases-comm-central/tree/master/mailnews/base/util