Known differences

Google Drive

A Google Drive with Docs and Sheets that answers Drive v2 and v3, Docs v1, Sheets v4 and uploads for Google's client libraries, plus Drive's MCP paths.

Vendor reference: https://developers.google.com/drive/api/reference/rest/v3 ↗. Machine-readable: compat/google-drive.json.

Surfaces

Kind	Path	Notes
REST	`/drive/v3`	files, permissions, comments, revisions, changes and watch channels; Drive v2 reads under `/drive/v2`
REST	`/upload/drive/v3`	simple, multipart and resumable uploads
REST	`/v1/documents`	Google Docs v1
REST	`/v4/spreadsheets`	Google Sheets v4
OAuth	`/token`	OAuth client credentials with Google-style scopes
MCP	`/mcp`	also at `/mcp/v1`, the path Google's Drive MCP server publishes

API versions: Drive v2 (reads), Drive v3, Docs v1, Sheets v4

Supported

Bearer tokens and the access_token query parameter Google also accepts
Google scopes drive, drive.readonly, drive.metadata.readonly, drive.file, documents, spreadsheets; a read-only signed token gets 403 insufficientPermissions on a write
401 authError with WWW-Authenticate: Bearer for a missing or unverifiable token, so an SDK refreshes its credential
The q search grammar
files.export up to 10 MiB, and exportLinks for larger exports
Watch channels with the sync handshake, per-file resource states, X-Goog-Changed and expiration

Not supported

apps.*, teamdrives.*, labels, access proposals, approvals, client-side encryption and operations.get
Sheets developerMetadata.* and the Docs and Sheets styling requests
Formula evaluation in Sheets
Converting an imported binary document (.doc, .odt, .xlsx) into Docs text

Known differences and test guidance

Scenario	Difference from Google Drive	In your tests
Sheets values	Values are stored verbatim; formulas are not evaluated and `FORMATTED_VALUE` returns the stored value.	Do not assert on computed cells or number formatting.
Revisions	Each content version is listed, but only the head revision's bytes are kept.	Do not download an older revision's content and compare it.
Sharing and permissions	Permissions are recorded and returned but not enforced per grantee; every token sees every file.	Do not use the replica to prove that a user cannot read a file.
Scopes with an opaque token	Scope checks only apply to IdP-signed tokens that carry a `scope` claim; an opaque bearer in open mode passes every request.	Request a signed token with a read-only scope from `/token` to test refusals.
Imported binary documents	Uploading a `.doc`, `.odt` or `.xlsx` as a Google Doc creates the Doc with empty text, so exporting it returns an empty body.	Do not assert on text extracted from an imported Office file.
Watch notifications	Delivery is in-process with three retries on 5xx; a notification is lost if your consumer is down for the whole backoff window, and channels do not survive a restart.	Re-read the changes feed after downtime rather than relying on every notification.
Quotas	No quota is enforced unless injected, and the injected status cannot be chosen per quota family.	Inject `throttle` or `quota_limit` to test backoff; do not test per-family quota handling.

Fault injection

Key	What the client sees
`throttle`	429 `userRateLimitExceeded` in Google's error envelope, with `Retry-After`
`fail_next`	The next N calls fail as `throttle` does, then clear
`quota_limit`	429 `quotaExceeded` in Google's error envelope
`error_rate`	500 `internalError` for the given fraction of calls
`latency_ms`	Fixed added latency on every data-plane request

Applies to every system

The hosted data plane is read-only: a write is refused with 403 writes_disabled. A SOQL, GraphQL or search POST is a read and is answered.
Faults are injected through POST /_admin/faults on a simulator you run yourself; POST /_admin/faults/reset clears them.
Rate limits do not happen on their own unless a page says so. Use fault injection to exercise a client's backoff.
Distributions come from aggregated metadata sketches of data Eon backs up; no customer records; all Era data is simulated.