Create assignment or Create Grade via Web Service

Hey All, 

I'm attempting to send student grades from an external application into Moodle (2.8+) but I haven't figured out how to do this as of yet.  It seems like the web services that exist to send grades require an assignment and there is no way to create an assignment in the web services.  Is this correct?  

I guess the work around would be to create a plugin to create the assignment?  

Any thoughts on how to handle this with the native web services?  I guess there is no direct access into the grade book that doesn't require an assignment? 

Thanks,
Jared