I am working with Engagement Designer / Zang Studio Call REST Service integration task. Is there a way that I can manipulate the content of the REST URI in my workflow prior to execution of the Call REST Service task? The situation is that I am hitting a web service that uses HTTP GET and needs parameters... like this... https://my.webservice.org/query?q='SomeText'&phone='e164number' where e164number should be the callingnumber from the start event.

Hi Neil,
The path variable or the request parameter is in the curly brackets {}. Its name should contain only alphanumeric characters “-” and “_”. For example,
http://host:port/your-rest-resources/{pathVar1}/{pathVar2}/...

After that click Retrieve and tool will generate a schema for you where you can map the values of your variables.

Quoting from the help file:

"Input schema (mandatory) – Click Retrieve to generate the input schema of the Call Rest task based on the input in the Rest URI, Customized Headers and Payload fields, so ensure that all those fields are configured properly first. The schema is based on the input from these fields and is not based on anything retrieved remotely. Click the Show checkbox to view the generated input schema. The input schema allows you to do input mapping."

Thank you Vishal! That was exactly what I needed to learn about at this point :=)