USPS Webhooks

USPS delivers webhooks through the Subscriptions - Tracking API (v3.2). You create a subscription (POST /subscriptions) with a listenerURL, filterProperties (by Mailer ID or tracking number), and an optional 32-char secret. USPS then POSTs a notification to your listener URL every time a tracked package updates.

When to Use This Skill

• How do I receive USPS tracking webhooks?
• How do I verify the USPS X-HMAC webhook signature?
• How do I create a USPS tracking subscription?
• How do I handle Delivered or Out for Delivery tracking events?
• Why is my USPS webhook signature verification failing?

Verification (core)