How do I mock the Google Sheets API locally?

Install stunt, add a one-service block to stunt.yaml (adapter: embedded:gsheets-style), and run stunt up. You get a local, stateful stand-in for Google Sheets API v4 — 10 routes over rest — with no remote account, no network, and no bills.

Is the Google Sheets API mock data synthetic?

Yes — entirely. The adapter returns generated data only; stunt's adapter lint rejects real-looking secrets and PII at build time. It simulates the shape and behavior of Google Sheets API (routes, status codes, pagination, webhooks), never real records.

← all adapters

gsheets-style

simulates Google Sheets API v4

restadapter v0.1.010 routes

verification

SDKverified with google-api-go-client v0.293.0· surface 10 · not implemented 4 · differs 3

use it

# add to stunt.yaml
services:
  gsheets:
    adapter: embedded:gsheets-style

# then
$ stunt up

The embedded: source extracts this adapter from the binary — no git clone, fully offline.

how to mock the Google Sheets API locally

Install stunt, paste the service block above into stunt.yaml, run stunt up — then point your client at localhost instead of Google Sheets API. It works offline, keeps state across requests and restarts, and every response is synthetic: the route shapes, status codes, pagination, and webhook delivery follow the real Google Sheets API v4 surface — the data is fake, the behavior is real.

backing stores

spreadsheetscells

api surface (10)

generated from the adapter manifest — exactly what boots, nothing more · covers 58% of the real API's 17 routes (derived from sdk google-api-go-client @ v0.293.0)

10 routes

POST/v4/spreadsheets

GET/v4/spreadsheets/{spreadsheetId}/values:batchGet

POST/v4/spreadsheets/{spreadsheetId}/values:batchGet

POST/v4/spreadsheets/{spreadsheetId}/values:batchUpdate

POST/v4/spreadsheets/{spreadsheetId}/sheets

POST/v4/spreadsheets/{ss_id_or_verb}

GET/v4/spreadsheets/{spreadsheetId}

GET/v4/spreadsheets/{spreadsheetId}/values/{range}

PUT/v4/spreadsheets/{spreadsheetId}/values/{range}

POST/v4/spreadsheets/{spreadsheetId}/values/{range_verb}

SDK-verified behaviors (8)

✓Spreadsheets.Create + Get round-trip
✓Values.Update + Values.Get round-trip an A1 range
✓Values.Get MajorDimension=COLUMNS transposes the grid
✓Values.Append writes after the last populated row
✓Values.BatchUpdate writes multiple ranges in one call
✓Values.BatchGet reads a range over GET query params
✓Spreadsheets.BatchUpdate addSheet adds a tab Values can write to
✓Get on an unknown spreadsheet -> googleapi 404

Not implemented (4)

No row-only A1 ranges (1:5) or quoted sheet titles
No copyTo, named ranges, developer metadata, or byDataFilter endpoints
batchUpdate limited to 4 request types; no insertDimension, mergeCells, sortRange
No valueRenderOption or dateTimeRenderOption on values reads

Differs from the real API (3)

Repeated ranges query params collapse to the first value (engine query params are single-valued)
Cell values always come back as strings; numeric cells stringify as floats (42 -> "42.0"), no USER_ENTERED/RAW typing
Spreadsheet get ignores fields= and returns the full object

full scorecard →

want more of the Google Sheets API surface? adapters are YAML + Starlark — the authoring guide covers adding routes, fixtures, and state machines. Open an issue for anything big first, or just file a PR — merged routes ship in the next release.