Connect WordPress to WhatsApp API: Complete Technical Guide 2025

Overview

What this guide covers

WordPress's hook system (actions and filters) is the cleanest integration point. Every meaningful event in WordPress fires an action hook, you attach a function to that hook, and it calls WA.Expert API. No plugin needed. For non-developers, several WordPress plugins provide a visual interface.

Integration approach	Complexity	Best for
WP Action Hooks + functions.php	⭐⭐ Medium: PHP knowledge	Most direct. Add code to theme's functions.php or a custom plugin.
WP REST API endpoint trigger	⭐⭐ Medium: REST API knowledge	External trigger via WordPress REST API → your custom endpoint → WA.Expert.
Contact Form 7 / Gravity Forms hook	⭐ Easy, form plugin + PHP snippet	Fire WhatsApp on any CF7 or Gravity Form submission.
WooCommerce order hooks	⭐ Easy. WooCommerce + PHP snippet	WooCommerce order status changes → WhatsApp. Most popular WP use case.
Plugin (WA.Expert WP plugin)	⭐ Easy, no code	Install WA.Expert WordPress plugin, no PHP needed.

Integration Methods

How to connect: all methods explained

Method 1 WooCommerce Order Hooks: Most Popular

1

Add code to functions.php or custom plugin

Open Appearance → Theme File Editor → functions.php (or create a custom plugin for better practice). All WooCommerce + WhatsApp code goes here.

2

Hook into WooCommerce order status changes

Use add_action("woocommerce_order_status_{status}", $callback, 10, 2). Replace {status} with: processing (payment received), completed (order fulfilled), or shipped (custom status). The callback receives $order_id and $order.

3

Get customer phone from order

Use $order = wc_get_order($order_id). Then $phone = $order->get_billing_phone(). This gets the phone number entered at checkout. WA.Expert normalises Indian formats automatically.

4

Call WA.Expert API via wp_remote_post

Use WordPress's built-in wp_remote_post() function, safer than raw cURL in WP. Pass the WA.Expert API endpoint, headers, and JSON body. Check wp_is_wp_error() on the response.

5

Test with a sandbox order

Place a test order in WooCommerce (use WooCommerce's Test Mode). Check your phone for the WhatsApp. Check PHP error log for any issues (wp-content/debug.log if WP_DEBUG_LOG is enabled).

// WordPress functions.php
// WooCommerce: WhatsApp on payment received

add_action('woocommerce_order_status_processing',
  function($order_id) {
    $order = wc_get_order($order_id);
    $phone = $order->get_billing_phone();
    $name  = $order->get_billing_first_name();
    $total = $order->get_total();
    $num   = $order->get_order_number();
    
    if (!$phone) return;
    
    wp_remote_post('https://api.wa.expert/v1/send', [
      'headers' => [
        'Authorization' => 'Bearer YOUR_API_KEY',
        'Content-Type'  => 'application/json',
      ],
      'body' => json_encode([
        'to'       => $phone,
        'template' => 'wc_order_confirm',
        'variables'=> ['name'=>$name, 'order'=>$num, 'total'=>$total],
      ]),
      'timeout' => 15,
    ]);
  }, 10, 1
);

Use a custom plugin (not functions.php) for production code, theme updates will overwrite functions.php. Create a file wp-content/plugins/waexpert-integration/waexpert-integration.php with the plugin header comment and your hooks.

Method 2 Contact Form 7 + WhatsApp

1

Add hook after CF7 submission

Use wpcf7_mail_sent action, fires every time a CF7 form is submitted successfully. Hook: add_action("wpcf7_mail_sent", $callback).

2

Access form data

In callback: $submission = WPCF7_Submission::get_instance(). $data = $submission->get_posted_data(). Access fields by name: $data["your-phone"], $data["your-name"], $data["your-message"].

3

Add a phone field to your CF7 form

In CF7 form editor: add [tel your-phone] field with acceptance validation. This collects the phone for WhatsApp. Label it "WhatsApp Number" to increase fill rate.

4

Call WA.Expert API

Same wp_remote_post() approach as WooCommerce. Map form fields to WhatsApp template variables.

// WordPress: Contact Form 7 → WhatsApp

add_action('wpcf7_mail_sent', function($cf7) {
  $sub   = WPCF7_Submission::get_instance();
  $data  = $sub->get_posted_data();
  $phone = $data['your-phone'] ?? '';
  $name  = $data['your-name']  ?? '';
  
  if (!$phone) return;
  
  wp_remote_post('https://api.wa.expert/v1/send', [
    'headers' => ['Authorization'=>'Bearer YOUR_KEY',
                   'Content-Type'=>'application/json'],
    'body' => json_encode([
      'to'       => $phone,
      'template' => 'cf7_confirmation',
      'variables'=> ['name' => $name],
    ]),
  ]);
});

FAQ

Common questions

Which WordPress hooks fire for which events?

Key WordPress + WooCommerce hooks for WhatsApp: wpcf7_mail_sent (Contact Form 7 submit), gform_after_submission (Gravity Forms), woocommerce_order_status_processing (payment received), woocommerce_order_status_completed (order fulfilled), user_register (new WP user), comment_post (new comment), publish_post (post published). Each passes relevant data to your callback function.

Should I put WhatsApp code in functions.php or a custom plugin?

Always use a custom plugin for production code, functions.php is overwritten when you update your theme. Create a minimal plugin: wp-content/plugins/waexpert-hooks/waexpert-hooks.php with a plugin header and your add_action() calls. This survives theme updates and can be activated/deactivated independently.

How do I handle errors when WA.Expert API is unavailable?

wp_remote_post() returns a WP_Error object on connection failure. Always check: if (!is_wp_error($response)) { process success } else { log_error }. Use error_log() to log failures to the PHP error log. Consider a retry queue using WP cron (wp_schedule_single_event) for critical notifications.

Can I trigger WhatsApp from Gravity Forms?

Yes. Gravity Forms uses the gform_after_submission hook. It passes $entry (form data) and $form (form definition). Access fields by ID: $entry["1"] for field ID 1. Map the phone field (add a Phone field type in GF) to the WA.Expert "to" parameter.

Does this work with WordPress.com (hosted)?

WordPress.com does not allow custom PHP code or custom plugins. This integration requires self-hosted WordPress (WordPress.org) where you have access to the file system and can add code to plugins or functions.php. For WordPress.com, use Zapier's WordPress integration (requires Business plan) as a workaround.

How do I store API keys securely in WordPress?

Never hardcode API keys in functions.php. Use WordPress options: add_option("waexpert_api_key", "YOUR_KEY") via Settings page, or define("WAEXPERT_API_KEY", "YOUR_KEY") in wp-config.php (outside web root). Access in code: get_option("waexpert_api_key") or the constant WAEXPERT_API_KEY. The wp-config.php approach is most secure.

Related Guides

More connection guides

Ready to connect WordPress to WhatsApp?

Three lines of PHP in your functions.php and every WooCommerce order fires a WhatsApp. Or install the WA.Expert WP plugin for zero-code setup.

Start Free Trial → Talk to a Developer

Connect WordPress to WhatsApp API: Hooks, REST API & Plugin Methods