The addons.mozilla.org (AMO) external API can be used by users and developers to get information about add-ons available on AMO, and to submit new add-on versions for signing. It’s also used by Firefox for recommendations, among other things, by the web-ext tool, and internally within the addons.mozilla.org website.
We plan to shut down Version 3 (v3) of the AMO API on December 31, 2021. If you have any personal scripts that rely on v3 of the API, or if you interact with the API through other means, we recommend that you switch to the stable v4. You don’t need to take any action if you don’t use the AMO API directly. The AMO API v3 is entirely unconnected to manifest v3 for the WebExtensions API, which is the umbrella project for major changes to the extensions platform itself.
Roughly five years ago, we introduced v3 of the AMO API for add-on signing. Since then, we have continued developing additional versions of the API to fulfill new requirements, but have maintained v3 to preserve backwards compatibility. However, having to maintain multiple different versions has become a burden. This is why we’re planning to update dependent projects to use v4 of the API soon and shut down v3 at the end of the year.
You can find more information about v3 and v4 on our API documentation site. When updating your scripts, we suggest just making the change from “/v3/” to “/v4” and seeing if everything still works – in most cases it will.
Feel free to contact us if you have any difficulties.