Native messaging

• 10/06/2020
• 5 minutes to read

In this article

Extensions communicate with a native Win32 application installed on a user's device using message passing APIs. The native application host sends and receives messages with extensions using standard input and standard output. Extensions using native messaging are installed in Microsoft Edge similar to any other extension. However, native applications are not installed or managed by Microsoft Edge.

To acquire the extension and native application host, you have two distribution models.

• Package your extension and the host together. When a user installs the package, both the extension and the host are installed.
• Install your extension using the Microsoft Edge Add-ons store, and your extension prompts users to install the host.

To create your extension to send and receive messages with native application hosts, refer to the following steps.

Step 1 - Add permissions to the extension manifest

Add the nativeMessaging permission to the manifest.json file of the extension. The following code snippet is an example of manifest.json.

    {
          "name": "Native Messaging Example",
          "version": "1.0",
          "manifest_version": 2, 
          "description": "Send a message to a native application.",
          "app": { 
              "launch": { 
                  "local_path": "main.html" } 
                 }, 
          "icons": { 
              "128": "icon-128.png"}, 
          "permissions": ["nativeMessaging"] 
    }

Step 2 - Create your native messaging host manifest file

Native applications must provide a native messaging host manifest file. The manifest file contains the path to the native messaging host runtime, the method of communication with the extension, and a list of allowed extensions to which it communicates. The browser reads and validates the native messaging host manifest. The browser does not install or manage the native messaging host manifest file.

    {
        "name": "com.my_company.my_application",
        "description": "My Application",
        "path": "C:\\Program Files\\My Application\\chrome_native_messaging_host.exe",
        "type": "stdio",
        "allowed_origins": [
            "chrome-extension://knldjmfmopnpolahpmmgbagdohdnhkik/"
        ]
    }

The host manifest file must be a valid JSON file that contains the following keys.

"allowed_origins": ["chrome-extension://{microsoft_catalog_extension_id}"]

Sideload your extension to test native messaging with the host.
To sideload your extension during development and retrieve microsoft_catalog_extension_id, complete the following steps.

1. Navigate to edge://extensions, and then turn on the Developer mode toggle button.
2. Choose Load unpacked, and then select your extension package to sideload.
3. Choose OK.
4. Navigate to edge://extensions page and verify your extension is listed.
5. Copy the key from microsoft_catalog_extension_id (ID) from the extension listing on the page.

When you are ready to distribute your extension to users, publish your extension to the Microsoft Edge add-ons store. The extension ID of the published extension may differ from the ID used while sideloading your extension. If the ID changed, update allowed_origins in the host manifest file with the ID of your published extension.

Step 3 - Copy the native messaging host manifest file to your system

The final step involves copying the native messaging host manifest file to your computer, and ensuring it is configured correctly. To ensure your manifest file is placed in the expected location, complete the following the steps. The location varies by platform.

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