This is a collection of MailExtensions (Thunderbird add-ons based on WebExtension technology) to showcase how the available WebExtension APIs can be used in Thunderbird. Each example exists for Manifest V2 and V3. The MV3 compatible versions include comments to highlight the required changes.
| Sample Extension | Description |
|---|---|
| addressBooks | Use the addressbooks, contacts, and mailingLists APIs and its dependencies. |
| apiList | List all available APIs in different windows: tabs, options, message compose and message display window. It uses the tabs API to inject scripts and css into the message compose and message display windows. |
| awaitPopup | Open a blocking popup and await user feedback. |
| composeBody | Use the compose API to access and manipulate the content of the message compose window. |
| composeScript | Use the composeScript API to access and manipulate the content of the message compose window. |
| dropbox | Use the cloudFile (a.k.a. FileLink) API to upload attachments to dropbox. |
| experiment | Show how to write an Experiment API including a function and an event and how to listen to the custom event. |
| experiment.openSearchDialog | Use an Experiment to open the message search dialog. The Experiment has been created with the Experiment Generator. |
| experiment.prefMigration | Use an Experiment to migrate preferences from the legacy pref system to the WebExtension local storage. |
| experiment.restart | Use an Experiment to add a Restart entry to Thunderbird's file menu and to perform a Thunderbird restart. |
| mailTabs | Use the mailTabs APIs to manipulate the appearance of the main Thunderbird window. |
| managedStorage | Use storage.managed to access data defined by enterprise policies. |
| messageDisplay | Use the messageDisplay and messageDisplayAction APIs to show how to add a button to the message header, and how to react when a message is displayed. |
| messageDisplayScript | Use the messageDisplayScript API to display a banner with information from the currently selected message along with a button to trigger an action in the background script via runtime.sendMessage. |
| messageDisplayScript.pdfPreview | Use the listAttachments() and getAttachmentFile() functions of the messages API to extract attached PDFs and images, and uses the messageDisplayScript API to display an inline preview directly in the message window. |
| optIn | Ask the user for extended consent before using the add-on. |
| quickFilter | Use the mailTabs, menus and messages APIs to add a Filter context menu to the message list which can set certain quickfilter settings. |
| sobriety | Shows how the compose.onBeforeSend event can be used: Opening a composeAction popup in the composition window when an email is about to be send, to request confirmation. |
| theme_experiment | A theme using the theme_experiment API to change the color of the chat icon. |
To run any of the listed extensions, clone or download this repository and either:
- zip the directory of your choice (
manifest.jsonshould be at the top level of the zip file) and install it like any other Add-On in Thunderbird. - select "Debug Add-Ons" from the Add-On Manager menu, click "Load Temporary Add-On" and select
manifest.jsonfrom your source (or any other file part of your Add-On). Temporary loaded Add-Ons do not need to be zipped.