New urlbar API for experimental add-ons

Shane Caraveo scaraveo at
Fri Dec 23 17:40:04 UTC 2016

You might want to look at the omnibox api (which landed recently on 
nightly) and see how it may fit and/or overlap with your proposed api, 
and how it might be extended to include new features you're looking at.

Otherwise, it would be interesting to see this as a webextension experiment.

I'm happy to provide some assistance when you get to a point that it's 
reasonable to try making the webextension api.

On 2016-12-22 6:17 PM, Drew Willcoxon wrote:
> I'm working on a new API to let add-ons modify the urlbar popup,
> primarily for add-ons developed by internal Mozilla teams and Mozilla
> partners. Over the past year different teams have been interested in
> shipping experimental urlbar UXes as part of things like Test Pilot and
> Shield studies. They've faced a few problems. One is XUL, XBL, XPCOM,
> etc., because often these teams aren't as familiar with Firefox
> development as the front-end team is. The second is that it's just not
> easy enough to modify the urlbar popup even if you do know front-end
> tech. The third problem is that there are only a couple of people on the
> front-end team who work on the urlbar, Marco and me, and we're a bottleneck.
> The new API is supposed to address those problems. It's based on Web
> tech: HTML, not XUL/XBL, no XPCOM, etc., basically letting you replace
> the popup contents with a Web page.
> I'd like to gather feedback, if you have any, especially from people at
> Mozilla who could potentially use such an API. There's a design document
> here:
> Thanks.
> _______________________________________________
> firefox-dev mailing list
> firefox-dev at

More information about the firefox-dev mailing list