In order for this example to work you must first install the native messaging host from the host directory.

On Windows: Run install_host.bat script in the host directory. This script installs the native messaging host for the current user, by creating a registry key HKEY_CURRENT_USER\SOFTWARE\Google\Chrome\NativeMessagingHosts\com.google.chrome.example.echo and setting its default value to the full path to host\com.google.chrome.example.echo-win.json . If you want to install the native messaging host for all users, change HKCU to HKLM. Note that you need to have python installed.

On Mac and Linux: Run install_host.sh script in the host directory: host/install_host.sh By default the host is installed only for the user who runs the script, but if you run it with admin privileges (i.e. 'sudo host/install_host.sh'), then the host will be installed for all users. You can later use host/uninstall_host.sh to uninstall the host.

The host application is adapted to Python 3.8.

The web page is located in the web directory. Upload it to your web hosting (running on localhost or from local drive will not work!), then update ext/manifest.json.