There is only one way to authenticate GroupDocs Cloud REST APIs: by using OAuth 2.0 protocol with JWT Bearer Token.
The JWT token is extracted and validated by our APIs from the Authorization request header.
OAuth 2.0 OAuth 2.0 is an authorization framework that enables your applications to obtain access to data to different APIs.
OAuth provides authorization flows for web and desktop applications, and mobile devices.
What is a JSON Web Token (JWT)?...Total Product Family GroupDocs.Viewer Product Solution GroupDocs...GroupDocs.Total Cloud Product Family / REST API Overview / Authenticating...