Auto-activate license after a product purchase in WordPress Easy Digital Downloads.

easy-digital-downloads_auto-activate-license-at-purcahse.php

<?php

// Auto Activate EDD License if Custom Field is True -- by X-Raym
function edd_auto_activate_activate_license( $license_id, $download_id, $payment_id ) {

	// Only specific download get auto activation (custom field)
	if ( ! get_field( 'auto-activate', $download_id ) )
		return false;

	$store_url = get_site_url(); // Multilingual site friendly
	
	$license_key = get_field( '_edd_sl_key', $license_id ); // Get license key from license post ID

	// data to send in our API request
	$api_params = array(
		'edd_action' => 'activate_license',
		'license'    => $license_key,
		'item_id'    => $download_id, // the name of our product in EDD
		'url'        => $store_url // Must have an URL so that license check "license" return "valid".
	);
    
	// Call the custom API.
	$response = wp_remote_post( $store_url , array(
		'timeout'   => 15,
		'sslverify' => false,
		'body'      => $api_params
	) );

	// make sure the response came back okay
	if ( is_wp_error( $response ) )
		return false;

	// decode the license data
	//$license_data = json_decode( wp_remote_retrieve_body( $response ) ); // For debugging purpose

}
add_action( 'edd_sl_store_license', 'edd_auto_activate_activate_license', 10, 3 ); // Hook when license is created