Formula Support

Writing Formulas

Use inputFormat: "USER_ENTERED" — Sheets API parses values starting with = as formulas:

// Cell update
await cell.update({
  value: "=SUM(A1:A10)",
  inputFormat: "USER_ENTERED",
})

// Row update
await row.update({
  values: ["=B1*C1", "=A1+B1"],
  inputFormat: "USER_ENTERED",
})

// Append
await tab.append({
  values: ["=SUM(D2:D10)", "=AVERAGE(E2:E10)"],
  inputFormat: "USER_ENTERED",
})

Plain values (no = prefix) are stored as strings even with USER_ENTERED.

Reading Formulas

Use valueRenderOption: "FORMULA" to get formula strings instead of computed values:

// Returns formula strings
const rows = await tab.values({ valueRenderOption: "FORMULA" })

// Single row
const row = await tab.getRow({
  serialNo: 1,
  valueRenderOption: "FORMULA",
})

// Single cell
const cell = await tab.getCell({
  cellName: "A1",
  valueRenderOption: "FORMULA",
})

Default behavior (no render option) returns computed values via FORMATTED_VALUE.