Barcode scanning is part of your phone API. So you start with that. Shopify has no real interest in providing you code to manage scanning since that would imply they support a bazillion Android and iOS things related to the phone camera. If you can wire up bar code scanning in your phone and get the scanned data in your code, THEN you can easily hook up to Shopify API codes to work with inventory, or any other applications where barcode scanning might be useful. Right?