Set an externally installed extension to automatically update

This article applies to externally installed extensions; that is, extensions that are distributed via an approach other than Partner Center; see Alternative ways to distribute an extension. This article doesn't apply to extensions that you publish using the Partner Center developer dashboard; for that distribution approach, see Update a Microsoft Edge extension.

Every few hours, Microsoft Edge checks whether each installed extension or app has an update URL. To specify an update URL for your extension, use the update_url field in the manifest. The update_url field in the manifest points to a location that can complete an update check. For each update_url, this URL sends requests for updated manifest XML files. If the update manifest XML file lists a newer extension or app version, Microsoft Edge downloads and installs the newer version. The same process works for manual updates, where the new .crx file must be signed with the same private key as the currently installed version.

In order to maintain user privacy, Microsoft Edge doesn't send any Cookie headers with auto-update manifest requests, and ignores any Set-Cookie headers in the responses to those requests.

When you set your extension to automatically update on users' machines, your extension shares the following benefits with Microsoft Edge:

• Incorporate bug and security fixes.
• Add new features or performance enhancements.
• Improve the user interface.

The Microsoft Edge Add-ons website hosts your extensions, and you can update your extension using the same mechanism as Microsoft Edge. You don't control the update mechanism.

(Previously, non-store-based extensions were supported. Also, previously, you updated the native binaries and the extension at the same time.)

Update URL

If you host your own extension or app, you must add the update_url field to your manifest.json file. The following code snippet shows an example of the update_url field:

{
  "name": "My extension",
  ...
  "update_url": "http://contoso.com/mytestextension/updates.xml",
  ...
}

Update manifest

The updated manifest returned by the server should be an XML document; for example:

<?xml version='1.0' encoding='UTF-8'?>
<gupdate xmlns='http://www.google.com/update2/response' protocol='2.0'>
  <app appid='aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'>
    <updatecheck codebase='http://contoso.com/mytestextension/mte_v2.crx' version='2.0' />
  </app>
</gupdate>

The updated manifest XML file defines the following attributes:

The update manifest XML file can contain information about multiple extensions, by including multiple <app> elements.

Testing

Microsoft Edge automatically checks for updates of extensions every few hours. To update extensions immediately, go to edge://extensions, turn on the Developer mode toggle, and then click the Update button.

Advanced usage: request parameters

The basic mechanism to update using parameters is simple. To automatically update your extension:

1. Upload your static XML file on your web server, such as Apache.
2. Update the XML file as you release new versions of your extensions.

Take advantage of the fact that some parameters added to the update manifest request indicate the extension ID and version. You can use the same update URL for all your extensions, instead of a static XML file. To use the same update URL for all your extensions, point to a URL that runs dynamic server-side code that tests the parameters.

The following example demonstrates the format of the request parameters of update URL:

?x={extension_data}

In this example, {extension_data} is a URL-encoded string that uses the following format.

id={id}&v={version}

For example, the following two extensions both point to the same update URL http://contoso.com/extension_updates.php.

• Extension 1
  • ID: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
  • update URL: http://contoso.com/extension_updates.php
  • Version: 1.1
• Extension 2
  • ID: bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
  • update URL: http://contoso.com/extension_updates.php
  • Version: 0.4

The following examples are requests to update each extension.

http://contoso.com/extension_updates.php?x=id%3Daaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa%26v%3D1.1

http://contoso.com/extension_updates.php?x=id%3Dbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb%26v%3D0.4

You can also list multiple extensions in a single request for each unique update URL. The following example merges the previous requests into a single request:

http://contoso.com/extension_updates.php?x=id%3Daaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa%26v%3D1.1&x=id%3Dbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb%26v%3D0.4

If you send a single request and the number of installed extensions that use the same update URL is too long, the update check issues more GET requests. A GET request URL is too long if it's approximately 2000 characters.

In a future release, instead of issuing multiple GET requests, a single POST request might be issued, with the request parameters in the POST body.

Advanced usage: minimum browser version

As new APIs are released for the Microsoft Edge extensions system, you might want to release an updated version of your extension or app that only works with newer versions of Microsoft Edge. When Microsoft Edge is automatically updated, it can take a few days before most of your users update to that new release.

To ensure that a specific update applies only to Microsoft Edge versions that are current or newer than a specific version, add the prodversionmin attribute in your update manifest.

For example, in the following code, the prodversionmin attribute value of 3.0.193.0 specifies that your app is automatically updated to version 2.0 only when the user is running Microsoft Edge 3.0.193.0 or newer:

<?xml version='1.0' encoding='UTF-8'?>
<gupdate xmlns='http://www.google.com/update2/response' protocol='2.0'>
  <app appid='aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'>
    <updatecheck codebase='http://contoso.com/mytestextension/mte_v2.crx' version='2.0' prodversionmin='3.0.193.0' />
  </app>
</gupdate>

See also

• Alternative ways to distribute an extension
• Update a Microsoft Edge extension
• Partner Center developer dashboard

Chrome Dev docs:

• Autoupdating

This work is licensed under a Creative Commons Attribution 4.0 International License.