Problem on deploying new WebExtension scriptly

Jerry Krinock jerry at
Thu Nov 16 16:28:13 UTC 2017

> On 201711-16, at 00:26, 朱旻 <minmin3772 at> wrote:
> Hi, guys from Firefox team: 
>       I'm a developer of FF Addon on OS X.
>       Recently I've just ported my legacy Addon to new WebExtension and got a problem. 
>       My addon is self-host, that is instead of uploading on AMO, I deploy it with my own app. I used to copy signed XPI file to user's profile folder, and it can be automatically recognized and installed by FF. Yet the new WebExtension XPI doesn't work like that. Every time I copied it to profile/extension folder, the XPI just disappeared after FF restart.

Welcome to the new world.  In order to install extensions nowadays, your native app or script should invoke the `open` command on the .xpi file.  If Firefox is not running, it will launch into its default profile and present a popover asking the user for permission to install.  If Firefox is running, it will show that popover in the frontmost tab and, or course, install it into whatever profile it happens to be running in.

The new world has challenges for user experience:

(a) You must check to see if more than one profile is exists, and if so instruct the user to (re)-launch Firefox into the desired profile.

(b) If the user clicks in the wrong window, or is for whatever reason not attentive to the popover, the popover will disappear and the user is left scratching their head.  (I hope I live long enough to see popovers to go out of style.)

I presume that the old way of “side loading” was disabled because it was thought to be insecure to allow extensions to be installed without user interaction.  You can try to argue with security, but you will always lose :))

More information about the Dev-addons mailing list