Real-time progress of mail pieces can be accessed through our webhooks feature, an easy way to get notifications on events happening asynchronously on Lob's side. Once webhooks are successfully set up on the dashboard, Lob will "push" you notifications when mail pieces are created, when they receive USPS scans such as "In Local Area" or "Processed for Delivery", or any other event you subscribe to.
Please view our Webhooks Integration Guide for more details on how to integrate. Additionally, the full list of event types available for subscription can be found here.