I don't know if you have found any solution for your question yet, but in case you are still interested, you can test the following:
var theData = {"features": [
{
"geometry": {
"x": -13316097.345,
"y": 5861939.546999998
},
"attributes": {
"Column1": "Value1",
"Column2": "Value2"
}
}
]};
another way that I'd recommend, and actually is worked for me, is to add the "features" parameter at the end of the url string:
var theData = [{ "geometry": { "x": -13316097.345, "y": 5861939.546999998 },
"attributes": { "Column1": "Value1", "Column2": "Value2" }
} ];
$.ajax({
url: "http://myhostname/arcgis/rest/services/myservice/FeatureServer/0/addFeatures" + JSON.stringify(theData)
, dataType: 'html' // the datatype must be html
, type: 'POST'
//, data: theData - remove this part
, success: function (data, textStatus, jqXHR) {
......