Great question! We haven't yet integrated a scheduler into Clause, so at the moment you need to use an external scheduler to periodically execute your Smart Clause®.

Rest assured that we will be integrating a declarative mechanism to schedule contract evaluation into the platform in due course.

There are many cloud hosted services that can invoke a web service on a schedule. For example:

You can configure these services to perform an HTTP POST to the Trigger URL for your smart clause at specific intervals. The body of the HTTP POST should contain the JSON description of a suitable transaction defined by your template.