See the frictionless sign-in page for implementation guidance for Google SSO
in Classroom add-ons. The frictionless sign-in guide also refers
to the test plan that can be used to ensure your add-on is
following sign-in best practices.
Sign in flow
To reduce sign-in friction for users, Google Classroom provides the
login_hint query parameter when an iframe is opened. login_hint is a user's
unique Google ID, and is provided after the user has signed into your add-on
for the first time. This parameter provides context on the user that's signed
into Google Classroom. See our sign-in parameters guide page for a more
detailed discussion of these query parameters.
You must display a Google sign-in dialog if the login_hint query parameter of
the current Google Classroom user doesn't match any signed-in user of the
add-on. The button must adhere to Google's branding guidelines. If the user is
already signed in, they shouldn't be prompted to sign-in again.
Figure 1. Sign in flow when a user initially launches
your add-on.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-03-19 UTC."],[[["Google Classroom add-ons must utilize Google single sign-on (SSO) for user authentication and identification."],["Add-ons should provide a seamless sign-in experience by utilizing the `login_hint` query parameter and only prompting users to sign in when necessary."],["Add-ons can be installed individually by users or by a domain administrator for all users, with varying consent options."],["Google provides comprehensive resources and guidelines for implementing SSO, user sign-in, branding, and installation settings."]]],[]]
Figure 1. Sign in flow when a user initially launches
your add-on.