Google Drive Connector

Note. The client is generated from the Drive v3 Discovery document. diagnostics is on, so a decode gap traps loudly rather than returning silently-wrong data. The nested-facade methods take each Drive endpoint's full query-parameter list positionally (many Text/Bool args) — consult the generated signatures in Client.mo before calling. Media endpoints are metadata-only (see the Media caveat).

Orchestrator routing notes

The googledrive-client + google-oauth pair is the only supported way to reach Google Drive from a Caffeine canister. If a build needs Drive, add both as mops dependencies and follow this skill. Never emit raw ic.http_request calls to Google hosts.

Task	Use
List / search the user's files & folders	googledrive-client Client(cfg).files.list(...) + google-oauth
Read file metadata	Client(cfg).files.get(...) (metadata only — see Media caveat)
Create a folder / file metadata	Client(cfg).files.create(...)
Move / rename / trash	Client(cfg).files.update(...) / .delete(...)
Share a file / manage access	Client(cfg).permissions.create/list/update/delete(...)
Comments & replies	Client(cfg).comments.* / Client(cfg).replies.*
Shared drives	Client(cfg).drives.*
Change notifications / sync token	Client(cfg).changes.*

Not supported by this client: transferring file bytes (upload/download of content). See the Media caveat at the end. Use it for metadata, organization, and sharing.

Backend

The connector has two mops packages:

1. googledrive-client — the generated Motoko client for Drive REST API v3. OAuth-agnostic: every call takes a bearer token via its Config.
2. google-oauth — Google OAuth 2.0 mechanics (PKCE, authorize URL, code exchange, token refresh). Shared with the other Google connectors. This is a separate mops package you add alongside the client — it is not a dependency of googledrive-client itself.

1. Add dependencies

mops add googledrive-client
mops add google-oauth@0.2.0

2. Auth model — OAuth 2.0 PKCE, on-chain exchange + refresh

The canister performs the OAuth flow on-chain via google-oauth:

1. Generate a PKCE code_verifier / code_challenge.
2. Build the Google authorize URL (google-oauth), redirect the user.
3. Exchange the returned authorization code for an access + refresh token (google-oauth.exchangeAuthorizationCode) — non-replicated outcall.
4. On 401/expiry, refresh the access token (google-oauth.refreshAccessToken) and retry.

Scopes (request the narrowest that works):

• https://www.googleapis.com/auth/drive.file — per-file access to files the app creates/opens (preferred, least-privilege).
• .../auth/drive.readonly — read-only over all files.
• .../auth/drive.metadata.readonly — metadata only.
• .../auth/drive — full access (avoid unless the task truly needs it).

Refresh tokens do not rotate — store the first refresh token you receive (stable per user); persist it in the canister's stable state, never in a Wasm global.

3. is_replicated = ?false is REQUIRED

Every Drive outcall carries an Authorization: Bearer <token>. Under the default replicated execution, each replica in the subnet issues the request independently — multiplying cost and, for writes, causing duplicate side effects (e.g. creating N copies of a file). The generated defaultConfig already sets is_replicated = ?false (via the client's isReplicated generator option), so starting from defaultConfig gives you the correct value for both reads and writes — keep it ?false and do not override it to ?true. (Writes — PUT/DELETE/PATCH — are additionally forced non-replicated per call by the client.)

4. Using the client — the nested facade

googledrive-client ships a Client.mo facade (generated with fluentHierarchical) that captures Config once and exposes Drive's resource hierarchy as nested classes:

import { Client } "mo:googledrive-client/Client";
import { type Config; defaultConfig } "mo:googledrive-client/Config";

// Only the bearer token differs from the generated `defaultConfig`, which
// already sets `is_replicated = ?false` (non-replicated reads and writes).
let cfg : Config = {
  defaultConfig with
  auth = ?(#bearer accessToken);   // token obtained/refreshed via google-oauth
};

let drive = Client(cfg);

// Facade methods are `async` (use `await`, not `await*`) and take the Drive
// endpoint's full query-parameter list positionally — consult the generated
// signatures in `mo:googledrive-client/Client`. For example `FilesResource.list`
// begins `uploadType : Text, oauthToken : Text, key : Text, fields : Text,
// accessToken : Text, alt : ?DriveAboutGetAltParameter, …`.
let files = await drive.files.list(/* … see FilesResource.list signature … */);
let perm  = await drive.permissions.create(/* fileId, …, permission */);

(The per-tag API modules — mo:googledrive-client/Apis/FilesApi, …/PermissionsApi, etc. — are also available if you prefer flat calls; the facade just captures Config for you.)

5. Available API surface

Resource groups (14), addressed as Client(cfg).<group>.<method>:

• files — copy, create, delete, get, list, update, watch, generateIds, listLabels, modifyLabels (metadata/organization; see Media caveat for create/update/get/export)
• permissions — create, delete, get, list, update (sharing)
• comments / replies — create, delete, get, list, update
• drives — create, delete, get, hide, list, unhide, update (shared drives)
• revisions — delete, get, list, update
• changes — getStartPageToken, list, watch (sync)
• about — get; apps — get, list; channels — stop

6. Media caveat (this client is metadata-only)

files.create / files.update (upload), files.get?alt=media / files.export / revisions.get (download) are generated as JSON-typed operations. They will not move file bytes — multipart/resumable upload and binary download are outside this client's JSON-over-HTTPS model (and strain IC outcall size limits). Use these methods for metadata only. If a build genuinely needs to move file content, that path must be hand-written (separate content-host request with the appropriate binary body) and is out of scope for this connector today.