A client-side endpoint (can only be queried from the user's browser) that starts the Google OAuth flow. This endpoint generates the Google OAuth URL with all required fields and redirects the user to that URL. The user authenticates with Google before getting redirected back to Stytch. After verifying the request, Stytch redirects the user back to the discovery_redirect_url provided.
By default our Google OAuth integration requests the open_id, email, and profile scopes. You may add any additional Google API scopes (see here for a complete list) as a space separated list in the custom_scopes query parameter.
Once the user successfully authenticates with Google, they'll be redirected to the redirect URL that you provided at the start of the OAuth flow with a Stytch OAuth token. Collect the token from the URL query parameters, and call Authenticate Discovery OAuth to exchange it for an Intermediate Session Token. Intermediate Session Tokens can be used for various Discovery login flows and are valid for 10 minutes.