How to integrate carrier site using Rails application

I am integrating the UPS, USPS, DHL and FEDEX with my Rails application. For that I am using 'trackify' plugin to find the carrier type for given Tracking Number and f开发者_如何学JAVAor also finding the XML response from the respective tracking site.

I want a complete guide for each of the above about how to integrate tracking API's?

---

You need to go to the companies' sites themselves to get that information. Once you've done that then come back if you have any questions about actual implementation. Sorry for leaving this as an answer but I can't leave comments yet.