OAuth sign-in succeeds but the app reports 'Missing scope gmail.send'

Missing scope gmail.send

Verified 2026-10-06 · Confirmed by 0 builders · Trust 50/100

Cause

Google's consent screen shows a checkbox for each requested scope and the user can leave one unticked. Sign-in still succeeds, with fewer scopes than requested.

Fix

Repeat the sign-in and tick every scope checkbox on the consent screen. In your own apps, check the granted scopes in the token response and explain what is missing.

Apply

Compare the scope field of the token response with the scopes you requested before proceeding.

Affects: Google OAuth 2.0 consent screen, October 2026

Have your agent know this before it fails

claude mcp add --transport http footgun https://getfootgun.com/api/mcp