twilio-wp-plugin/includes/interface-twp-sms-provider.php

<?php
/**
 * SMS Provider Interface
 *
 * Interface for SMS providers (Twilio, Amazon SNS, etc.)
 */
interface TWP_SMS_Provider {

    /**
     * Send an SMS message
     *
     * @param string $to_number Recipient phone number (E.164 format)
     * @param string $message Message body
     * @param string $from_number Sender phone number (E.164 format)
     * @return array Response array with 'success' and 'data' or 'error'
     */
    public function send_sms($to_number, $message, $from_number = null);

    /**
     * Get provider name
     *
     * @return string Provider name
     */
    public function get_provider_name();

    /**
     * Validate provider configuration
     *
     * @return array Response array with 'success' and 'message' or 'error'
     */
    public function validate_configuration();
}