Google Sheets gadgets are read-only — could they write too?

[kei-tenkawa]

Google Docs gadgets can edit their document, but Google Spreadsheet gadgets can only read theirs, and it would be great if they could write too. Agents can analyse a sheet and then have to hand the result back for someone to paste in by hand, which is a shame when the doc equivalent just does it.

The gap looks like it is only in the Sheets side rather than anything structural:

• Scopes are spreadsheets.readonly + drive.metadata.readonly, against documents for docs (packages/gatekeeper-google/src/google.ts).
• sheets-api.ts exposes getSpreadsheet() and readRanges() and nothing else, while docs-api.ts has batchUpdate().
• The spreadsheet gatekeeper's applyAction / rejectAction / revertAction all throw "Google Sheets is read-only and implements no actions.", and getAutoApprovableActions() returns [].

Everything a write path needs seems to be there already on the docs side — EDIT_DOCUMENT_ACTION, PendingActionStore, in-order approval, and the invalidatedReason handling for a document that changed underneath a pending edit. Sheets would presumably want the same shape, with the values it is about to overwrite captured so revertAction has something to restore.

Is the read-only surface a deliberate call (revert being awkward for a large range, maybe), or just not built yet? Would love to see writes land here at some point.