How do I authenticate Web API?

Authenticate API requests using basic authentication with your email address and password, with your email address and an API token, or with an OAuth access token . All methods of authentication set the authorization header differently. Credentials sent in the payload or URL are not processed.

Using the [Authorize] Attribute Web API provides a built-in authorization filter, AuthorizeAttribute. This filter checks whether the user is authenticated. If not, it returns HTTP status code 401 (Unauthorized), without invoking the action.

ASP.NET Web API is a service which can be accessed over the HTTP by any client. So, providing security to the Web API is very important, which can be easily done with the process called Token based authentication .

In Basic Authentication, the user passes their credentials [user name and password] on a post request . At the WebAPI end, credentials are verified. If the credentials are valid, then a session will initiate to accept the subsequent requests without validating the user again.