Ensure OAuth Scope Includes Required Permissions

When integrating Google Drive functionality, make sure the OAuth scope provided during authentication includes the required permissions.

Initially, the scope I provided during user authentication was:

// @/lib/auth.config.ts

import { NextAuthConfig } from "next-auth";
import Google from "next-auth/providers/google";

export const authConfig: NextAuthConfig = {
  providers: [
    Google({
      authorization: {
        params: {
          scope: "https://www.googleapis.com/auth/drive.file",
          access_type: "offline",
          prompt: "consent",
        },
      },
    }),
  ],
};

This scope (https://www.googleapis.com/auth/drive.file) only allows access to files created or opened by the app. To gain broader access, I updated the scope to:

// @/lib/auth.config.ts

import { NextAuthConfig } from "next-auth";
import Google from "next-auth/providers/google";

export const authConfig: NextAuthConfig = {
  providers: [
    Google({
      authorization: {
        params: {
          scope: "https://www.googleapis.com/auth/drive",
          access_type: "offline",
          prompt: "consent",
        },
      },
    }),
  ],
};

With this change, the refresh and access tokens issued will include the https://www.googleapis.com/auth/drive scope, granting full access to the user's Google Drive.

In Node.js, the code is:

import { google } from 'googleapis';

async function getOAuthClient(accessToken,refreshToken) {

  const oauth2Client = new google.auth.OAuth2(
    process.env.GOOGLE_CLIENT_ID,
    process.env.GOOGLE_CLIENT_SECRET
  );

  oauth2Client.setCredentials({
    access_token: accessToken,
    refresh_token: refreshToken,
  });

  return oauth2Client;
}

// Set up the query string for the search
let query = "mimeType='application/vnd.google-apps.document'"; // Only Google Docs

// If a search query is provided, add it to the query
if (searchQuery) {
  query += ` and name contains '${searchQuery}'`;
}

const oauthClient = await getOAuthClient(tenant);
const drive = google.drive({ version: 'v3', auth: oauthClient });
const response = await drive.files.list({
  q: query,
  fields: 'files(id, name, createdTime, modifiedTime, webViewLink)',
  pageSize: 5,
  orderBy: 'modifiedTime desc',
  corpora: 'allDrives',
  includeItemsFromAllDrives: true,
  supportsAllDrives: true,
});

Additional Tips

• Test your API requests using Google’s API Explorer to ensure proper permissions and functionality:
  Google Drive API Explorer - Files: list

This resolved the issue for me. I hope it helps others facing similar problems!