# Trusted System

Trusted System's are a way to use Ripplestone in another application without requiring the user to sign on using the Ripplestone login form.

The calling application passes the trusted system name and user id in the query string and these are used to log the user on. The parameters are:

- System - the trusted system name.
- TSUID - the incoming user id for a user of a trusted system.

A URL to Ripplestone from a trusted system should look like:

http://machinename/Ripplestone/SignOn.aspx?System=TrustedSystem&TSUID=TrustedUserId