How do I get USPS Media Mail and Library Mail rates on EasyPost?
In order to receive USPS Media Mail or Library mail rates you will need set the Shipment Option special_rates_eligibility
to "USPS.MEDIAMAIL"
or "USPS.LIBRARYMAIL"
respectively. You can read more about this in our documentation here.
As a reminder, you'll need to set this in the Shipment Options array in order to display the correct rates.