≡ Add-on developer resources

• Introduction to add-on development

• "Hello world" extension tutorial

• Developer community

• Sample extensions (Github)

• Using Promises

• Additional resources on DTN

≡ Guides

• Strategies to avoid using innerHTML

• Working with WebExtension events

• Using runtime messages

• Working with message lists

• Working with vCard contacts

• Converting extensions to Manifest V3

Converting extensions to Manifest V3

Thunderbird 128 ESR is the first Thunderbird release to officially support Manifest Version 3.

A general introduction to Manifest V3 and the required changes is provided by extensionworkshop.com. Thunderbird’s add-on team made additional changes to its WebExtension APIs, to remove inconsistencies. This page documents these backward incompatible changes from Manifest V2 to Manifest V3.

Additionally, the examples in our sample repository have been converted to Manifest V3, and might give helpful insights.

accounts API

• Default value for the includeSubFolders parameter of list([includeSubFolders]) has been changed from true to false.

• Default value for the includeSubFolders parameter of get(accountId, [includeSubFolders]) has been changed from true to false.

• Default value for the includeSubFolders parameter of getDefault([includeSubFolders]) has been changed from true to false.

• The function accounts.setDefaultIdentity has been removed, use getDefault(accountId) instead.

• The folders property of the MailAccount type has been replaced by the rootFolder property.

• The type property of the MailAccount type uses local instead of none for local accounts.

contacts API

• Replaced by addressBooks.contacts API.

• The ContactNode type no longer has a ContactProperties property, but a vCard property. It is no longer possible to specify individual contact properties.

• The onUpdated event provides the entire old vCard in its second parameter, instead of individual changed properties.

• The parentId is no longer a dedicated parameter for query(queryInfo), but an optional property for its queryInfo parameter.

• The function create(parentId, vCard) expects a vCard for its second parameter, instead of individual properties. It also no longer has a dedicated parameter to specify an id, which is now provided via the vCard.

• The function update(id, vCard) expects a vCard for its second parameter, instead of individual properties.

mailingLists API

• Replaced by addressBooks.mailingLists API.

browserAction API

• Replaced by action API

commands API

• The built-in _execute_browser_action command shortcut for the commands manifest entry has been renamed to _execute_action.

compose API

• The id property of the ComposeRecipient type has been renamed to nodeId.

• The additionalFccFolder property of the ComposeDetails type has been replaced by the additionalFccFolderId property (expecting a MailFolderId).

• The overrideDefaultFccFolder property of the ComposeDetails type has been replaced by the overrideDefaultFccFolderId property (expecting a MailFolderId).

• The overrideDefaultFcc property of the ComposeDetails has been removed. An override can now be cleared by setting overrideDefaultFccFolderId to null.

composeScripts API

• Replaced by scripting.compose API.

folders API

• The type property of MailFolder has been removed. Use the specialUse property instead.

• The favorite property of MailFolderInfo has been removed. It is now available as a property of MailFolder.

• The type property of the queryInfo parameter of query([queryInfo]) has been removed. Use the specialUse property instead.

• Default value for the includeSubFolders parameter of get(folderId, [includeSubFolders]) has been changed from true to false.

• create(folderId, childName) no longer accepts a MailFolder or MailAccount for its first parameter, but a MailFolderId. Use MailAccount.rootFolder to specify the root of an account.

• rename(folderId, newName) no longer accepts a MailFolder for its first parameter, but a MailFolderId.

• move(sourceFolderId, destinationFolderId) no longer accepts a MailFolder or MailAccount for its parameters, but a MailFolderId. Use MailAccount.rootFolder to specify the root of an account.

• copy(sourceFolderId, destinationFolderId) no longer accepts a MailFolder or MailAccount for its parameters, but a MailFolderId. Use MailAccount.rootFolder to specify the root of an account.

• delete(folderId) no longer accepts a MailFolder for its first parameter, but a MailFolderId.

• update(folderId, updateProperties) no longer accepts a MailFolder for its first parameter, but a MailFolderId.

• getFolderInfo(folderId) no longer accepts a MailFolder for its first parameter, but a MailFolderId.

• getFolderCapabilities(folderId) no longer accepts a MailFolder for its first parameter, but a MailFolderId.

• getParentFolders(folderId, [includeSubFolders]) no longer accepts a MailFolder for its first parameter, but a MailFolderId.

• getSubFolders(folderId, [includeSubFolders]) no longer accepts a MailFolder for its first parameter, but a MailFolderId.

• Default value for the includeSubFolders parameter of getSubFolders(folderId, [includeSubFolders]) has been changed from true to false.

• markAsRead(folderId) no longer accepts a MailFolder for its first parameter, but a MailFolderId.

mailTabs API

• The mailTabs.getCurrent() function has been removed, use messenger.mailTabs.query({active:true, currentWindow: true}) instead.

• The id property of MailTab has been replaced by the tabId property.

• The viewType property of MailTab and MailTabProperties has been replaced by the groupType property.

• The displayedFolder property of MailTabProperties has been replaced by the displayedFolderId property, and no longer accepts a MailFolder, but a MailFolderId.

menus API

• The built-in _execute_browser_action shortcut for the command property of the createProperties parameter of create(createProperties, [callback]) has been renamed to _execute_action.

• The values browser_action and browser_action_menu of ContextType have been renamed to action and action_menu.

• The selectedAccount and selectedFolder properties have been removed from OnShowData and OnClickData. Use the selectedFolders property instead.

messageDisplay API

• The messageDisplay.onMessageDisplayed event has been removed, use onMessagesDisplayed instead.

• The onMessagesDisplayed event returns a MessageList instead of an array of MessageHeader.

• The messageDisplay.getDisplayedMessage() function has been removed, use getDisplayedMessages([tabId]) instead.

• The getDisplayedMessages([tabId]) function returns a MessageList instead of an array of MessageHeader.

messageDisplayScripts API

• Replaced by scripting.messageDisplay API.

messages API

• The list(folderId) function no longer accepts a MailFolder, but a MailFolderId.

• The default value for the data_format parameter of getRaw(message, [options]) has been changed from BinaryString to File.

• The queryInfo parameter of query([queryInfo]) no longer supports the folder property, use the folderId property instead.

• The queryInfo parameter of query([queryInfo]) no longer supports the unread property, use the read property instead.

• The move(messageIds, folderId, [options]) function no longer accepts a MailFolder, but a MailFolderId for its first parameter.

• The copy(messageIds, folderId, [options]) function no longer accepts a MailFolder, but a MailFolderId for its first parameter.

• The import(file, folderId, [properties]) function no longer accepts a MailFolder, but a MailFolderId for its second parameter.

• The messages.listTags(), messages.createTag() and messages.updateTag() functions have been replaced by list(), create([key], tag, color, [callback]) and update(key, updateProperties).

spaces API

• The id property of the queryInfo parameter of query([queryInfo]) has been renamed to spaceId.

spacesToolbar API

• The spacesToolbar API has been removed, use spaces API instead.

tabs API

• The mailTab property of the queryInfo parameter of query([queryInfo]) has been removed. Use the type property instead.

• The mailTab property of MailTab has been removed. Use the type property instead.

• The tabs.executeScript and tabs.insertCSS functions have been removed. Use scripting API, scripting.compose API or scripting.messageDisplay API instead. Note: It is no longer possible to execute a JavaScript string in Manifest V3.