Understanding A3L Authentication
For a brief introduction to A3L SDKs, see Understanding A3L SDKs.
A3L Authentication is an abstraction library for authentication, which enables your app to let a user sign in with their Google account. It supports both Android and Fire OS devices. The A3L Authentication SDK has a dependency on Google Sign-In for devices that support Google Play services and AppAuth for devices that don't support Google Play Services. AppAuth is a client-side SDK that uses OAuth 2.0 and OpenID Connect to authenticate and authorize users on native apps. The A3L Authentication API structure is similar to that of Google Sign-In so that the amount of effort you need to learn and implement the SDK is minimal.
How A3L Authentication works
A3L Authentication provides a single SDK that behaves differently depending on the device on which it's used, while keeping the user experience as similar as possible. A3L Authentication is an abstraction over Google Sign-In and AppAuth. The solution used by A3L Authentication depends on whether the device the app is used on supports Google Play services.
There are differences in the sign-in flow that depend on whether a device has Google Play services available. When a user signs in on a Google Play services supported device, they see an app-based authentication. On devices that don't support Google Play services, the authentication is Custom Tab based, and the user is redirected to a Custom Tab where they need to sign in. This is because, unlike Google's in-app sign-in, AppAuth provides a Custom Tab based sign-in.
The following table describes the features offered in A3L Authentication compared to AppAuth and Google Sign-In.
|Feature||Google Sign-In||AppAuth||A3L Authentication|
|Configuring Sign In|
|Fetching Profile Information|
|Authenticate with a backend server|
|Enabling Server-Side Access|
Login with Amazon and A3L Authentication
A3L Authentication is independent of Login with Amazon (LWA). LWA authenticates with Amazon's ID while A3L Authentication authenticates with Google's ID. Your app doesn't have to integrate with LWA to use A3L Authentication. If you have already developed an Android app that uses Google Sign-In and you want to port your app to the Amazon Appstore, consider using A3L Authentication rather than LWA. A3L Authentication can save you effort because it's syntactically similar to Google Sign-In and provides the same ID as Google Sign-In after authentication.
Last updated: May 19, 2023