This integration of X-Cart into the Samurai payment gateway uses the Server To Server method of integration.  
For more information on Server To Server: https://samurai.feefighters.com/developers/php/api-reference#server-to-server-payment-method-api

For more information on Samurai visit: http://samurai.feefighters.com
For the Samurai documentation visit: https://samurai.feefighters.com/developers
For customer support visit our chatroom: http://samurai.feefighters.com/chat

To use this plugin you require three account credentials:
1. merchant_key
2. merchant_password
3. processor_token

You can get those credentials at http://samurai.feefighters.com.  To sign up for a test account is free and takes 30 seconds.

This plugin includes the Samurai PHP client library, which is contained within the samurai-client-php directory of the 
payment directory.  

This plugin will be uploaded to the xcart marketplace, but the latest version will always be available at: 
https://github.com/FeeFighters/samurai-x-cart. When used from github please notice that the PHP library
is incorporated as a git submodule so you must run git submodule init; git submodule update to pull it down.