Getting Started with OAuth 2.0

Client Profiles, Access Tokens, and Authorization Flows

The first version of OAuth was designed primarily to handle API authorization for classic client-server web applications. The specification did not define how to handle authorization in mobile applications, desktop applications, JavaScript applications, browser extensions, or other situations. While each of these types of apps have been written using OAuth 1.0, the method of implementation is inconsistent and often suboptimal, as the protocol wasn’t designed for these cases.

OAuth 2.0 was architected with this variety of use cases in mind.

Client Profiles

OAuth 2.0 defines several important client profiles:

Server-side web application

An OAuth client running on a web server. The web application is accessed by a resource owner (user) and the application makes the appropriate API calls using a server-side programming language. The user has no access to the OAuth client secret or any access tokens issued by the authorization server.

Client-side application running in a web browser

An OAuth client running in a user’s web browser, where the client has access to the application code and/or API requests. The application could be distributed as JavaScript included in a web page, as a browser extension, or using a plug-in technology such as Flash. The OAuth credentials are not trusted to be kept confidential from the resource owner, so some API providers won’t issue client secrets for applications using this profile.

Native application

An OAuth ...