How to append data to spreadsheet via api?

I need to push data into a spreadsheet via api but cant find the documentation to this.

each call should append one row of data after the last row that contains data into a specific worksheet. like a csv that gets written over time so to say.

Hello @wuast94

In general, this can be done in following way with macro:

var oWorksheet = Api.GetSheet("Sheet1");
var data = "data to insert";
var oRange = oWorksheet.GetUsedRange();
var oCol = oRange.GetCols(1);
var oCount = oCol.GetCount();
oRange.GetCells(oCount+1, 1).SetValue(data);

This example uses following methods: GetSheet, GetUsedRange, GetCols, GetCount, GetCells and SetValue.

Basically, this macro counts rows in specified column and then gets a cell in the next row of the range and inserts predefined data into it.
To get last row firstly following logic is used: get number of all rows in the used range and add 1 extra to get next row after used ones. For this example rows are selected from column A with method GetCols.