Thunderbird WebExtension APIs

Thunderbird WebExtensions are very similar to those of Firefox. These documents assume you have some familiarity with building a WebExtension for Firefox. If not, it is highly recommended to begin by reading some of the MDN documentation on the subject.

WebExtension APIs are asynchronous, that is, they return a Promise object which resolves when ready. See Using Promises for more information about Promises.

The documents were generated automatically from the schema documents at mail/components/extensions/schemas.


This documentation is for pre-release versions of Thunderbird. See the “68” version for Thunderbird 68.


These APIs should be considered experimental and may change in the future. For any problems or feature requests please file a bug.

The following APIs are also included and work as they do in Firefox: