I'm not sure when they did it, but they've added this now. Use class DataValidationBuilder's requireCheckbox() method. Example:
function setCheckboxes() { // Assumes there's only one sheet var sheet = SpreadsheetApp.getActiveSheet(); // This represents ALL the data var dataRange = sheet.getDataRange(); /* Get checkbox range from sheet data range. Assumes checkboxes are on the left-most column */ var dataRangeRow = dataRange.getRow(); var dataRangeColumn = dataRange.getColumn(); var dataRangeLastRow = dataRange.getLastRow(); var checkboxRange = sheet.getRange( dataRangeRow, dataRangeColumn, dataRangeLastRow ); var enforceCheckbox = SpreadsheetApp.newDataValidation(); enforceCheckbox.requireCheckbox(); enforceCheckbox.setAllowInvalid(false); enforceCheckbox.build(); checkboxRange.setDataValidation(enforceCheckbox); } 