Can you get the value of a variable from a process published as webservices?

I don't understand the question.

Could you provide more detail on your use case?

The documentation here, https://docs.appian.com/suite/help/19.2/Designing_Web_APIs.html#templates, talks about how to create web services from templates, but it could include more detail.

If you want to call a process from a web API, follow that documentation referenced above - after you select `new web api` - select the "start process" create template.  That will guide you through the necessary parameters for starting an Appian process from a web service call.

I don't understand the question.

Could you provide more detail on your use case?

The documentation here, https://docs.appian.com/suite/help/19.2/Designing_Web_APIs.html#templates, talks about how to create web services from templates, but it could include more detail.

If you want to call a process from a web API, follow that documentation referenced above - after you select `new web api` - select the "start process" create template.  That will guide you through the necessary parameters for starting an Appian process from a web service call.

And to follow on Rob's comment, the response of your Web API can use fv!processInfo which includes values for all process variables in the process you started. You can use an expression to return only certain variables or format them in a certain way.