How to use javascript to directly interface with Google App Engine

[that an]

I'm looking for a way to use my javascript code to directly interface with the google app engine and with the datastore. 

I've already used the GWT/GAE Java SDK in Eclipse with varying levels of success, but I'm looking for a way to leverage the benefits of GAE & Google cloud server with the graphical UI strengths of writing javascript direct DOM manipulation on the client.   

Maybe I've missed something obvious, or something that is out there does it, but I've been searching for awhile now, and it just seems like Google is dancing around any direct client access to their App Engine and cloud datastore.  Strange, considering the GAE/GWT toolkits eventually need to convert python and java source into javascript.   

I've pretty much exhausted my leads so far - Any direction is greatly appreciated.