There are four different ways of providing an external program that makes incoming requests to Calpendo. You can choose the one that's most appropriate to the task you need to perform.
We have a REST API that provides RESTful access in JSON, XML or HTML, but currently only in read-only form. There's a read-only Query API that lets perform complex data queries by specifying conditions to filter which data to return as well as the columns you want. A Workflows Anonymous HTTP event is triggered whenever an http call is made to a subset of URLs, which enables you to run a workflow in response to a web browser or other program. Note that this is an anonymous API which means there is no logging in for this interface and you will be responsible for providing your own security arrangements. Finally, the API used by our standard web client is a JSON API that you can access, although only a small subset of the API is published. Amongst other things, this will allow you to run a workflow and go through authentication.