is correct extend the ajax function adding a method "websocket+json-rpc"?

is correct extend the ajax function adding a method "websocket+json-rpc"?

I'm interested on replace ajax calls by websockets and json-rpc calls,
but many javascripts i'm using are writen for use ajax.

Is correct to extends the ajax object, adding a new method? (existing methods are GET, POST, PUT)
There is some work similar this?

Thanks