# Add-on Development - [Introduction](https://developer.thunderbird.net/add-ons/about-add-ons.md): What you need to know about making add-ons for Thunderbird. - [What's new?](https://developer.thunderbird.net/add-ons/whats-new.md): The latest developments for Add-On developers. - [Manifest Version 3](https://developer.thunderbird.net/add-ons/whats-new/manifest-v3.md) - [A "Hello World" Extension Tutorial](https://developer.thunderbird.net/add-ons/hello-world-add-on.md): All the information you need to get your first Thunderbird extension up and running. - [Using WebExtension APIs](https://developer.thunderbird.net/add-ons/hello-world-add-on/using-webextension-apis.md): Extending the simple example extension to make use of WebExtension APIs. - [Using a Background Page](https://developer.thunderbird.net/add-ons/hello-world-add-on/using-a-background-page.md): Extending the example extension to use a background page. - [Using Content Scripts](https://developer.thunderbird.net/add-ons/hello-world-add-on/using-content-scripts.md): Extending the example extension to use a content script. - [A Guide to Extensions](https://developer.thunderbird.net/add-ons/mailextensions.md): How to create extensions for Thunderbird. - [Supported Manifest Keys](https://developer.thunderbird.net/add-ons/mailextensions/supported-manifest-keys.md): Descriptions of all manifest keys supported by Thunderbird. - [Supported UI Elements](https://developer.thunderbird.net/add-ons/mailextensions/supported-ui-elements.md): Descriptions and examples of MailExtension APIs to interact with Thunderbird's user interface. - [Supported WebExtension APIs](https://developer.thunderbird.net/add-ons/mailextensions/supported-webextension-api.md): Descriptions of all WebExtension API supported by Thunderbird. - [Introducing Experiments](https://developer.thunderbird.net/add-ons/mailextensions/experiments.md) - [A Guide to Themes](https://developer.thunderbird.net/add-ons/web-extension-themes.md): How to create themes for Thunderbird. - [Developer Community](https://developer.thunderbird.net/add-ons/community.md): Learn how to get in touch with the Thunderbird add-on developer community. - [Documentation & Resources](https://developer.thunderbird.net/add-ons/resources.md): A collection of the most important developer resources outside of developer.thunderbird.net. - [Tips and Tricks](https://developer.thunderbird.net/add-ons/resources/tips-and-tricks.md): Tips and tricks for successful Thunderbird add-on development. - [Add-on Update Guides](https://developer.thunderbird.net/add-ons/updating.md) - [Updates for Thunderbird 140](https://developer.thunderbird.net/add-ons/updating/updates-for-thunderbird-140.md) - [Update for Thunderbird 128](https://developer.thunderbird.net/add-ons/updating/tb128.md): Required steps to update add-ons for Thunderbird 128. - [Update for Thunderbird 115](https://developer.thunderbird.net/add-ons/updating/tb115.md): Required steps to update add-ons for Thunderbird 115. - [Adapt to Changes in Thunderbird 103-115](https://developer.thunderbird.net/add-ons/updating/tb115/adapt-to-changes-in-thunderbird-103-115.md) - [Update for Thunderbird 102](https://developer.thunderbird.net/add-ons/updating/tb102.md): Required steps to update add-ons for Thunderbird 102. - [Adapt to Changes in Thunderbird 92-102](https://developer.thunderbird.net/add-ons/updating/tb102/adapt-to-changes-in-thunderbird-92-102.md) - [Update for Thunderbird 91](https://developer.thunderbird.net/add-ons/updating/tb91.md): Required steps to update add-ons for Thunderbird 91. - [Adapt to Changes in Thunderbird 79-91](https://developer.thunderbird.net/add-ons/updating/tb91/changes.md) - [Update for Thunderbird 78](https://developer.thunderbird.net/add-ons/updating/tb78.md): Required steps to update add-ons for Thunderbird 78. - [Adapt to Changes in Thunderbird 69-78](https://developer.thunderbird.net/add-ons/updating/tb78/changes.md) - [Update for Thunderbird 68](https://developer.thunderbird.net/add-ons/updating/tb68.md): Required steps to update add-ons for Thunderbird 68. - [Adapt to Changes in Thunderbird 61-68](https://developer.thunderbird.net/add-ons/updating/tb68/changes.md) - [How to convert legacy extensions?](https://developer.thunderbird.net/add-ons/updating/historical-overview.md) - [Convert wrapped WebExtensions to modern WebExtensions](https://developer.thunderbird.net/add-ons/updating/historical-overview/wrapped-to-modern.md) - [Convert legacy WebExtensions to modern WebExtensions](https://developer.thunderbird.net/add-ons/updating/historical-overview/legacy-to-modern.md) - [Convert legacy overlay extension to legacy WebExtension](https://developer.thunderbird.net/add-ons/updating/historical-overview/overlays.md) - [Convert legacy bootstrapped extension to legacy WebExtension](https://developer.thunderbird.net/add-ons/updating/historical-overview/bootstrapped.md) --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://developer.thunderbird.net/add-ons.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.