Getting Started with OAuth 2.0

Enhanced Mobile App Authorization for Specific Providers

Some OAuth providers have built special mobile libraries or applications to make doing OAuth easier on devices and to improve the user experience.

For Google

On its Android operating system, Google provides a service called the AccountManager. Originally this service was designed to allow applications to request auth tokens for Google APIs using the proprietary ClientLogin mechanism. However, this service has been updated to support getting OAuth 2.0 access tokens for Google APIs.

In order to get an OAuth 2.0 access token, you simply need to call AccountManager.getAuthToken() to request a token using an authTokenType of oauth2:<scope>. For example, to request access to the Google Tasks API, specify an authTokenType of oauth2:https://www.googleapis.com/auth/tasks. Unfortunately, this literal string will be presented to users when they’re asked to grant access, so using this technique is not recommended. However, for some APIs, such as Google Tasks, there are aliases such as Manage Your Tasks that can be used in place of the oauth2:<scope> value to produce a much friendlier request.

After you call getAuthToken(), the account manager will ask the user to approve or deny the request using a native application prompt. If the user approves the request, the application will be issued an access_token value, which can be used in API requests.

The Google Tasks API team has created an article with more details on using this technique. Although ...