extending-wc-square.php

<?php

add_action('wc_square_loaded',function(){
	if (class_exists('Woocommerce_Square')) {		
		add_action( 'plugins_loaded', function(){
			
			// get WooCommerce_Square
			$wcsm = Woocommerce_Square::instance();
			
			// startup, (aka `Woocommerce_Square::init()` rebuilt)
			$wcsm->integration = new WC_Square_Integration();
			$wcsm_client = new WC_Square_Client();
			$access_token = get_option( 'woocommerce_square_merchant_access_token' );
			$wcsm_client->set_access_token( $access_token );
			$wcsm_client->set_merchant_id( $wcsm->integration->get_option( 'location' ) );
			$wcsm->square_client = $wcsm_client;
			$wcsm->square_connect = new WC_Square_Connect( $wcsm_client );
			
			// basic api call
			$response = $wcsm_client->request( 'Retrieving Products', 'modifier-lists' );
			
			// output
			echo "<pre>".print_r($response,true)."</pre>";
			die;
			
		});
	}
});