you can use $.param to assign data :
$http({
url: "http://example.appspot.com/rest/app",
method: "POST",
data: $.param({"foo":"bar"})
}).success(function(data, status, headers, config) {
$scope.data = data;
}).error(function(data, status, headers, config) {
$scope.status = status;
});
look at this : AngularJS + ASP.NET Web API Cross-Domain Issue