Example extensions
==================

To illustrate how to use the WebExtension APIs, we maintain a repository of example extensions at https://github.com/mdn/webextensions-examples. This article describes how to run these examples and lists the examples along with the WebExtension APIs they demonstrate.

These examples work in Firefox Nightly: most work in earlier versions of Firefox, but check the strict\_min\_version key in the extension's manifest.json to make sure.

**Warning:** Some examples work only on specific domains or pages. Details of any restrictions are provided in each example's readme file. None of the examples work in private browsing windows by default, see Extensions in Private Browsing for details.

To try these examples, clone the repository, then install and run the extension using one of these options:

* use the Load Temporary Add-on feature and open the extension from its source folder.
* install `web-ext`, open the extension's source folder at the command line, and use `web-ext run`.

The extension stays loaded until you restart Firefox.

**Warning:** Please do not submit these WebExtension examples to addons.mozilla.org (AMO); you do not have to sign the add-on WebExtension examples to run them.

If you want to contribute to the repository, send us a pull request.

| Name | Description | JavaScript APIs |
| --- | --- | --- |
| annotate-page | Displays a sidebar that lets you take notes on web pages. | `storage.local``tabs.onActivated``tabs.onUpdated``tabs.query``tabs.Tab``windows.getCurrent``windows​.Window` |
| apply-css | Adds a page action to the toolbar. Click the button to apply a red border using injected CSS. Click the button again to remove the CSS. | `pageAction.getTitle``pageAction.onClicked``pageAction.setIcon``pageAction.setTitle``pageAction.show``tabs.insertCSS``tabs.onUpdated``tabs.query``tabs.removeCSS``tabs.Tab` |
| beastify | Adds a browser action icon to the toolbar. Click the button to choose a beast. The active tab's body content is then replaced with a picture of the chosen beast. | `extension.getURL``runtime.onMessage``tabs.executeScript``tabs.insertCSS``tabs.query``tabs.removeCSS``tabs.sendMessage``tabs.Tab` |
| bookmark-it | Adds a bookmark button to the toolbar. Click the button to toggle a bookmark for the current page. | `bookmarks.create``bookmarks.onCreated``bookmarks.onRemoved``bookmarks.remove``bookmarks.search``browserAction.onClicked``browserAction.setIcon``browserAction.setTitle``tabs.onActivated``tabs.onUpdated``tabs.query``tabs.Tab``windows.onFocusChanged` |
| borderify | Adds a solid red border to all webpages matching mozilla.org. |  |
| chill-out | Show a page action after a period of inactivity. Show cat gifs when the page action is clicked. | `alarms.clearAll``alarms.create``alarms.onAlarm``pageAction.hide``pageAction.onClicked``pageAction.show``tabs.get``tabs.onActivated``tabs.onUpdated``tabs.query``tabs.update` |
| commands | Demonstrates using the commands API to set up a keyboard shortcut. The shortcut created is accessed using Ctrl+Shift+U (Command+Shift+U on a Mac). | `commands.getAll``commands.onCommand``commands.reset``commands.update``tabs.create` |
| content-script-register | Illustrates how an extension can register URL-matching content scripts at runtime. | `contentScripts.register``runtime.onMessage``runtime.sendMessage` |
| context-menu-copy-link-with-types | Add a context menu option to links to copy the link to the clipboard, as plain text and as a link in rich HTML. | `contextMenus.create``contextMenus.onClicked``tabs.executeScript` |
| contextual-identities | List, create, and remove contextual identities. | `contextualIdentities.query``tabs.create``tabs.query``tabs.remove` |
| cookie-bg-picker | Allows the user to customize the background color and tiled pattern on sites they visit, and also saves their preferences via a cookie, reapplying them whenever they revisit a site they previously customized. | `cookies.get``cookies.onChanged``cookies.remove``cookies.set``extension.getURL``runtime.onMessage``tabs.onActivated``tabs.onUpdated``tabs.query``tabs.Tab``tabs.sendMessage` |
| devtools-panels | Demonstrates some of the devtools APIs. | `devtools.inspectedWindow``devtools.panels``runtime.getURL``runtime.onMessage``runtime.sendMessage``tabs.executeScript` |
| discogs-search | Demonstrates adding a custom search engine with the chrome\_settings\_overrides key. |  |
| dnr-block-only | Demonstrates how to block network requests without host permissions using the declarativeNetRequest API with the `declarative\_net\_request` manifest key. | `declarativeNetRequest.Rule``declarativeNetRequest.RuleAction``declarativeNetRequest.RuleCondition` |
| dnr-dynamic-with-options | Demonstrates a generic way to request host permissions and register declarativeNetRequest rules to modify network requests, without any install-time permission warnings. The options\_ui page offers a way to request permissions and register DNR rules. | `declarativeNetRequest.Rule``declarativeNetRequest.getDynamicRules``declarativeNetRequest.getSessionRules``declarativeNetRequest.updateDynamicRules``declarativeNetRequest.updateSessionRules``permissions.getAll``permissions.remove``permissions.request` |
| dnr-redirect-url | Demonstrates multiple ways to redirect requests using the declarativeNetRequest API through the `declarative\_net\_request` manifest key. Demonstrates aspects of Manifest Version 3 (MV3): action, host\_permissions, and web\_accessible\_resources, and includes a comparison with Manifest Version 2 (MV2). | `declarativeNetRequest.Redirect``declarativeNetRequest.Rule``declarativeNetRequest.RuleAction``declarativeNetRequest.RuleCondition``declarativeNetRequest.URLTransform``permissions.contains``permissions.remove``permissions.request` |
| dynamic-theme | Dynamic theme example | `alarms.create``alarms.onAlarm``theme.update` |
| emoji-substitution | Replaces words with emojis. |  |
| eslint-example | Demonstrates how to configure an extension with eslint. |  |
| export-helpers | Demonstrates how to use export helpers like cloneInto to share objects with page scripts. | `notifications.create``runtime.onMessage``runtime.sendMessage` |
| favourite-colour | An example options page, letting you store your favourite colour. | `browserAction.onClicked``runtime.openOptionsPage``storage.managed``storage.sync` |
| find-across-tabs | Demonstration of the find API. | `browserAction.onClicked``extension.getBackgroundPage``find.find``find.highlightResults``runtime.getURL``runtime.onMessage``runtime.sendMessage``tabs.create``tabs.query``tabs.Tab` |
| firefox-code-search | Demonstrates how to use the omnibox API. | `omnibox.onInputChanged``omnibox.onInputEntered``omnibox.setDefaultSuggestion``tabs.create``tabs.update` |
| forget-it | Demonstrates how to use the browsingData API. | `browserAction.onClicked``browsingData.remove``notifications.create``storage.local` |
| google-userinfo | Demonstrates how to use the identity API. | `browserAction.onClicked``identity.getRedirectURL``identity.launchWebAuthFlow``notifications.create` |
| history-deleter | History API demo: deletes history items for a given domain | `history.deleteUrl``history.search``pageAction.show``tabs.onUpdated``tabs.query` |
| http-response | Demonstrates how to rewrite HTTP responses using the webRequest.filterResponseData() API. | `webRequest.filterResponseData``webRequest.onBeforeRequest` |
| imagify | Using a sidebar, illustrates the use of file picker and drag and drop. A content script replaces the current page content with the chosen image. | `extension.getURL``runtime.onMessage``tabs.executeScript``tabs.query``tabs.sendMessage` |
| latest-download | Shows the last downloaded item, and lets you open or delete it. | `downloads.erase``downloads.getFileIcon``downloads.open``downloads.removeFile``downloads.search` |
| list-cookies | This extensions list the cookies in the active tab. | `cookies.getAll``tabs.query` |
| menu-accesskey-visible | Shows how to set up a single letter access key for a menu item. | `i18n.getMessage``menus.update``menus.create``menus.onClicked` |
| menu-demo | Demonstrates adding and manipulating menu items using the menus API. | `i18n.getMessage``menus.create``menus.onClicked``menus.remove``menus.update``runtime.lastError``tabs.executeScript` |
| menu-labelled-open | Shows how an extension can listen for the display of a menu and then add, remove, or update its menu items. | `menus.create``menus.onClicked``menus.onShown``menus.refresh``menus.update``tabs.update` |
| menu-remove-element | Shows how to detect the page element at the cursor position and remove that element, or a parent element, from the page. This example includes use of the polyfill, illustrating cross-browser extension development. | `menus.create``menus.onClicked``menus.getTargetElement``pageAction.openPopup``pageAction.show``tabs.executeScript` |
| menu-search | Illustrates how to retrieve a list of search engines and issue a search request, using search engine details added to the context menu for selected text. | `search.search``search.get``menus.create``menus.onClicked` |
| mocha-client-tests | This example shows two methods of testing an extension: running tests from within the extension, and running tests from the command line using Karma. | `runtime.onMessage``runtime.sendMessage` |
| native-messaging | Example of native messaging, including a Python application and an extension which exchanges messages with it. | `browserAction.onClicked``runtime.connectNative` |
| navigation-stats | Demonstration of the webNavigation API, showing basic stats about which pages you've visited. | `storage.local``webNavigation.onCommitted``webNavigation.onCompleted` |
| notify-link-clicks-i18n | Shows a localized notification when the user clicks on links. | `extension.getURL``i18n.getMessage``notifications.create``runtime.onMessage``runtime.sendMessage` |
| open-my-page-button | Adds a browser action icon to the toolbar. When the browser action is clicked, the add-on opens a page that was packaged with it. | `browserAction.onClicked``tabs.create` |
| page-to-extension-messaging | Demonstrates how a web page and a content script can exchange messages. Visit https://mdn.github.io/webextensions-examples/content-script-page-script-messaging.html for the demo. |  |
| permissions | Demonstrates optional permissions using the permissions API. | `browserAction.onClicked``permissions.getAll``permissions.remove``permissions.request``runtime.getURL``tabs.create` |
| private-browsing-theme | Example dynamic theme: sets a dark theme for private windows. | `theme.reset``theme.update``windows.getAll``windows.onCreated` |
| proxy-blocker | Uses the proxy API to block requests to hosts specified on a list. | `extension.getURL``proxy.onRequest``proxy.onError``storage.local``storage.onChanged` |
| quicknote | Allows the user to make quick notes by clicking a button and entering text into the resulting popup. The notes are saved in storage. | `storage.local` |
| root-cert-stats | Shows how to get details about a request's TLS connection. | `webRequest.getSecurityInfo` |
| runtime-examples | Demo of various runtime APIs. | `browserAction.onClicked``notifications.create``runtime.getManifest``runtime.onInstalled``runtime.reload` |
| selection-to-clipboard | Demonstrates how to write to the clipboard from a content script |  |
| session-state | Demonstrates how to retrieve extension-defined state from restored tabs. | `menus.create``menus.onClicked``sessions.getTabValue``sessions.setTabValue``tabs.insertCSS``tabs.onCreated``tabs.onUpdated``tabs.query` |
| store-collected-images | Demonstrates how to use the idb-file-storage library to store and manipulate files in an extension. | `browserAction.onClicked``contextMenus.create``contextMenus.onClicked``runtime.onMessage``runtime.sendMessage``tabs.create``windows.create` |
| stored-credentials | Performs basic authentication by supplying stored credentials. | `storage.local``webRequest.onAuthRequired``webRequest.onCompleted``webRequest.onErrorOccurred` |
| tabs-tabs-tabs | Demonstrates tab manipulation: opening, closing, moving, zooming tabs. | `browserAction.setBadgeBackgroundColor``browserAction.setBadgeText``tabs.create``tabs.duplicate``tabs.getZoom``tabs.move``tabs.onCreated``tabs.onMoved``tabs.onRemoved``tabs.query``tabs.reload``tabs.remove``tabs.setZoom``tabs.Tab``tabs.update` |
| theme-integrated-sidebar | A sidebar that integrates with the current theme. | `theme.getCurrent``theme.onUpdated``windows.getCurrent` |
| theme-switcher | An example of how to use the management API for themes. | `management.getAll``management.setEnabled` |
| themes | A collection of themes illustrating:* weta\_fade: a basic theme employing a single image specified in `theme_frame:`.
* weta\_fade\_chrome: the weta\_fade theme implemented with Chrome compatible manifest keys.
* weta\_tiled: a theme using a tiled image.
* weta\_mirror: a theme using multiple images and aligning those images in the header.
* animated: use of an animated PNG.
 |  |
| top-sites | Demonstration of the topSites API. | `topSites.get` |
| user-agent-rewriter | Demonstrates using the webRequest API to rewrite the User-Agent HTTP header. | `extension.getBackgroundPage``webRequest.onBeforeSendHeaders` |
| user-script-register | Illustrates how an extension can register URL-matching user scripts at runtime. | `userScripts.register``runtime.onMessage``runtime.sendMessage` |
| webpack-modules | Demonstrates how to use webpack to package npm modules in an extension. | `runtime.onMessage``runtime.sendMessage` |
| window-manipulator | Demonstrates how to manipulate windows: opening, closing, resizing windows. | `windows.create``windows.getAll``windows.getCurrent``windows.remove``windows.update``windows​.Window` |
| open-irc-links | Demonstrates the use of protocol handlers. |  |