---
title: "Can I set up single sign-on so users sign in once across several Catalyst apps or projects?"
url: https://docs.catalyst.zoho.com/en/faq/cloud-scale/single-sign-on-across-apps/
description: "No. Catalyst CloudScale Authentication doesn't offer single sign-on across Catalyst applications. Each application keeps its own users: a person who signs up to …"
last_updated: 2026-11-13T05:00:22Z
service: CloudScale
type: faq
---

No. Catalyst CloudScale Authentication doesn't offer single sign-on across Catalyst applications. Each application keeps its own users: a person who signs up to two of your applications gets a separate identity, with its own ZUID and Org ID, in each one, and signs in to each separately. A user's sign-in token from one project can't call another project's protected functions.

What you can do instead:
1. Put apps that must share their users in one Catalyst project, so they use one set of users.
2. Enable the same social login, such as Zoho, Google or Microsoft 365, in every application, so users sign in everywhere with the same provider account instead of a separate password.
3. Use Third-party Authentication with an identity provider that offers single sign-on. The provider verifies the user, and your function in each project creates the Catalyst session with a custom token (`generateCustomToken()`).

Note: Social logins and Third-party Authentication require **Public Signup** to be enabled.

Refer to the [Users help page](https://docs.catalyst.zoho.com/en/cloud-scale/help/authentication/user-management/users/introduction/) for how user identities work across applications.