A drop-in authentication solution for sports fans

Long story short ...

Fans United provides a drop-in auth solution that handles the UI flows for signing in users with email addresses and passwords, phone numbers, and with popular federated identity providers, including Google Sign-In and Facebook Login. Fans United is based on Google Firebase Authentication, it integrates tightly with other Firebase services, and it leverages industry standards like OAuth 2.0 and OpenID Connect, so it can be easily integrated with your custom backend.

Identity providers integration

Fans United supports all major identity providers, including Google, Facebook, Microsoft, Apple, Twitter, Yahoo and more. All of these are enabled with a click of a button.

Custom authentication

If you have your own, existing sign-in system, you can connect it to the Firebase Authentication SDK and your users can gain access to all the features Fans United provides.

Anonymous authentication

We also support anonymous authentication. You can allow unauthenticated users to use your services by creating temporary anonymous accounts. If the user later chooses to sign up, you can upgrade the anonymous account to a regular account, so the user can continue where they left off.

How does it work?

To sign a user into your app, you first get authentication credentials from the user. These credentials can be the user's email address and password, or an OAuth token from a federated identity provider. Then, you pass these credentials to the Firebase Authentication SDK. Firebase services will then verify those credentials and return a response to the client. After a successful sign in, you can access the user's basic profile information, and you can control the user's access to data stored in other Firebase products. You can also use the provided authentication token to verify the identity of users in Fans United backend services. Fans United can use your existing Firebase project, or if you don’t have one, we can create one for you. You have access to this project and in case you decide to not use Fans United services, you get to keep all your users and your authentication services are practically intact.


There’s no need to migrate. You can use the Firebase custom authentication and all Fans United services will just work. You can reed more on custom authentication here.

No, we do not limit your number of users. However, if you are using the anonymous authentication feature, Firebase is limiting you to 100 mln anonymous users, which should be plenty.