To automatically trigger Google’s Indexing API on WordPress, you’ll need to follow these steps:
Set Up Google Cloud Project:
Go to the Google Cloud Console and create a new project.
Enable the Indexing API for the project. Search for “Indexing API” in the API Library and enable it.
Create Service Account:
In the Google Cloud Console, navigate to IAM & Admin > Service Accounts.
Create a new service account, and give it a name. Make sure to grant it the proper role, specifically the “Indexer” role.
Generate a new JSON key for the service account and download it to your computer. This key is crucial for authentication.
Install a Plugin:
You can use a plugin like “WP Indexing API” or any similar plugin that supports Google’s Indexing API.
Alternatively, if you prefer a custom solution, you can use a custom code snippet in your theme’s functions.php or a custom plugin.
Authenticate with the Service Account:
If using a plugin, follow the plugin’s instructions to input your service account’s JSON key.
If coding it yourself, include a library like Google API PHP Client in your project and set up your script to authenticate using the JSON key.
Add Code to Trigger Indexing:
Use the following sample code to create a function that can be called when a post or page is published or updated:

php
function trigger_indexing_api( $post_id ) {
// Check if post type is ‘post’ or ‘page’
if ( get_post_type( $post_id ) !== ‘post’ && get_post_type( $post_id ) !== ‘page’ ) {
return;
}

// Replace with your service account credentials
$serviceAccountPath = ‘/path/to/your/service-account.json’;
putenv(‘GOOGLE_APPLICATION_CREDENTIALS=’ . $serviceAccountPath);

// Include the necessary Google Client Library classes
require ‘path/to/google-api-php-client/vendor/autoload.php’;

$client = new Google_Client();
$client->useApplicationDefaultCredentials();
$client->setScopes(Google_Service_Indexing::INDEXING);

$service = new Google_Service_Indexing($client);

// Set the URL of the post/page
$url = get_permalink($post_id);

// Prepare the indexing request
$body = new Google_Service_Indexing_UrlNotification();
$body->setUrl($url);
$body->setType(“URL_UPDATED”);

// Execute the indexing request
$service->urlNotifications->publish($body);
}

// Hook the function to the ‘save_post’ action
add_action(‘save_post’, ‘trigger_indexing_api’);
Confirm Indexing Requests:
After implementation, you can validate if the URL was indexed successfully by checking the Google Search Console under “URL Inspection”.
Monitor for Errors:
Make sure to log any errors that might occur during the indexing process. Google provides tools for checking the status of your indexing requests, and you can use the logging functions in WordPress to keep track of errors.

By following these steps, you can automate the process of triggering Google’s Indexing API through your WordPress site whenever content is published or updated.