Simple API for adding efforts/#4183

To be able to use streber for logging activities I would like to use a simple start-stop mechanism.
Im thinking something like this:
The user executes a local application (this would minimize to the app-tray) The application signs in to streber and acquires a valid authentication cookie and retrieves a list of projects and tasks.
The user can via a menu in the application start a timer on a given project/task.
The user can later on stop the timer, and the application would submit the effort into streber.

I would be happy to create a .net/mono application for this, all I need is an API :)