Upsert Rows (Smart Update/Insert)

2D array of data rows to upsert. IMPORTANT: If 'headers' is NOT provided, the FIRST row is treated as column headers and remaining rows as data - so you need at least 2 rows (1 header + 1 data). If 'headers' IS provided separately, then ALL rows in this array are treated as data rows. Each row should have the same number of values as headers. If a row has MORE values than headers: with strict_mode=true (default), an error is returned showing which rows are affected; with strict_mode=false, extra values are silently truncated. If a row has FEWER values than headers, an error is returned during execution. Cell values can be strings, numbers, booleans, or null. Example with headers provided: headers=['Email','Status'], rows=[['john@ex.com','Active']] (1 data row). Example without headers: rows=[['Email','Status'],['john@ex.com','Active']] (row 1 = headers, row 2 = data).

List of column names for the data. These will be matched against sheet headers. If a column doesn't exist in the sheet, it will be added automatically. Order doesn't need to match sheet order. Can be auto-derived from the first row in 'rows' if not provided. Example inputs: ['Email', 'Phone', 'Status'] for contact updates, ['Lead ID', 'Name', 'Score'] for CRM, ['SKU', 'Stock', 'Price'] for inventory.

The column NAME (header text) to use as unique identifier for matching rows. Must be an actual header name from the sheet (e.g., 'Email', 'Lead ID', 'SKU'), NOT a column letter (e.g., 'A', 'B', 'C'). If you provide a column letter like 'A', it will be automatically converted to the header name at that column position. If neither 'key_column' nor 'key_column_index' is provided, defaults to the first column (index 0).

The name of the sheet/tab within the spreadsheet. Note: Google Sheets creates default sheets with localized names based on account language (e.g., 'Sheet1' for English, '工作表1' for Chinese, 'Hoja1' for Spanish, 'Feuille1' for French, 'Planilha1' for Portuguese, 'Лист1' for Russian). If you specify a common default name and the sheet is not found, the action will automatically use the first sheet if only one exists.

Controls how rows with mismatched column counts are handled. When True (default), an error is returned if any row has more values than headers - the error message shows exactly which rows are affected and what values would need to be removed. When False, extra values are silently truncated to match the header count. Set to False only if you explicitly want automatic truncation of extra values.

Cell where the table starts (where headers are located). Defaults to 'A1'. Use this if your table is offset (e.g., 'C5', 'D10').

The ID of the spreadsheet. Must be a non-empty string, typically a 44-character alphanumeric string found in the spreadsheet URL.

The 0-based column index to use as unique identifier for matching rows. Alternative to 'key_column' - will be converted to column name using headers. If neither 'key_column' nor 'key_column_index' is provided, defaults to 0 (first column). Example: 0 for first column, 1 for second column.

Internal field to track input normalization (e.g., row truncation). Not part of API.