Can Growth plan support third-party authentication for users?

Yes, you can authenticate users on the Growth plan, with one distinction worth understanding.

If your team wants to sign in using providers like Google or GitHub, this is supported on the Growth plan as part of Sanity's standard login options. Users can authenticate through these accounts without any additional setup.

If you need to connect your own corporate identity provider through SAML SSO — for example Okta, Google Workspace, Azure Entra ID, PingIdentity, or another SAML-compliant provider — this is available on the Enterprise plan. SAML SSO lets you control project access centrally through your identity provider, with users authenticated through your IdP and assigned roles automatically.

The Enterprise plan also includes advanced role mapping, which automatically maps your identity provider groups to specific Sanity roles, along with unlimited custom roles and support for larger teams.

So if the requirement is simply letting team members log in with Google or GitHub, the Growth plan covers it. If the requirement is routing authentication through your organization's own identity provider via SAML, that's part of the Enterprise plan. You can see how SAML SSO is configured in the SSO setup guide.