Below is a list of Carrier Tracking APIs we've worked with and information about them. These are all SOAP / XML APIs. Please let us know if you'd like more information about any of them.
EasyPost offers one Tracking API for all your packages. You can track USPS, FedEx, UPS, and more packages using our API. With our Webhooks, you can also set endpoints to be updated when a package status changes. Documentation is located here: Tracking and Webhooks Documentation