This repository is the home of the USPS Shipping Module, supporting Zen Cart versions 1.5.6 through 1.5.8.
USPS interface API documentation: https://www.usps.com/business/web-tools-apis/documentation-updates.htm
Zen Cart download link: https://www.zen-cart.com/downloads.php?do=file&id=1292
Zen Cart support-thread link: https://www.zen-cart.com/showthread.php?227284-USPS-Shipping-Module-Support-Thread
This version supports the newly-introduced USPS Ground Advantage™ shipping-method and removes the USPS Retail Ground and various USPS First Class domestic shipping methods.
On an upgrade, if you were an early-adopter of version 2023-07-05 K11i-beta1, an upgrade to 2023-07-12 K11i will be automatic. Otherwise, you'll need to capture the current module's settings, "Remove", re-"Install" and re-apply the previous settings!
Refer to the in-module comments present in /extras/includes/classes/observers/auto.usps_overrides.php for additional information. To use this module, you'll make your modifications and then copy that file to your site's /includes/classes/observers/auto.usps_overrides.php. The module, as shipped, implements the customization provided by @Ajeh in this Zen Cart posting.