RestSharp

Authenticators

RestSharp includes authenticators for basic HTTP (Authorization header), NTLM and parameter-based systems.

Basic Authentication

The HttpBasicAuthenticator allows you pass a username and password as a basic Authorization header using a base64 encoded string.

var client = new RestClient("http://example.com");
client.Authenticator = new HttpBasicAuthenticator("username", "password");
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OAuth1

For OAuth1 authentication the OAuth1Authenticator class provides static methods to help generate an OAuth authenticator.

Request token

This method requires a consumerKey and consumerSecret to authenticate.

var client = new RestClient("http://example.com");
client.Authenticator = OAuth1Authenticator.ForRequestToken(consumerKey, consumerSecret);
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Access token

This method retrieves an access token when provided consumerKey, consumerSecret, oauthToken, and oauthTokenSecret.

client.Authenticator = OAuth1Authenticator.ForAccessToken(
    consumerKey, consumerSecret, oauthToken, oauthTokenSecret
);
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This method also includes an optional parameter to specify the OAuthSignatureMethod.

client.Authenticator = OAuth1Authenticator.ForAccessToken(
    consumerKey, consumerSecret, oauthToken, oauthTokenSecret, 
    OAuthSignatureMethod.PlainText
);
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0-legged OAuth

The same access token authenticator can be used in 0-legged OAuth scenarios by providing null for the consumerSecret.

client.Authenticator = OAuth1Authenticator.ForAccessToken(
    consumerKey, null, oauthToken, oauthTokenSecret
);
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OAuth2

RestSharp has two very simple authenticators to send the access token as part of the request.

OAuth2UriQueryParameterAuthenticator accepts the access token as the only constructor argument, and it will send the provided token as a query parameter oauth_token.

OAuth2AuthorizationRequestHeaderAuthenticator has two constructors. One only accepts a single argument, which is the access token. The other constructor also allows you to specify the token type. The authenticator will then add an Authorization header using the specified token type or OAuth as the default token type, and the token itself.

For example:

client.Authenticator = new OAuth2AuthorizationRequestHeaderAuthenticator(
    token, "Bearer"
);
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The code above will tell RestSharp to send the bearer token with each request as a header. Essentially, the code above does the same as the sample for JwtAuthenticator below.

As those authenticators don't do much to get the token itself, you might be interested in looking at our sample OAuth2 authenticator, which requests the token on its own.

JWT

The JWT authentication can be supported by using JwtAuthenticator. It is a very simple class that can be constructed like this:

var authenticator = new JwtAuthenticator(myToken);
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For each request, it will add an Authorization header with the value Bearer <your token>.

As you might need to refresh the token from, you can use the SetBearerToken method to update the token.

Custom Authenticator

You can write your own implementation by implementing IAuthenticator and registering it with your RestClient:

var client = new RestClient();
client.Authenticator = new SuperAuthenticator(); // implements IAuthenticator
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The Authenticate method is the very first thing called upon calling RestClient.Execute or RestClient.Execute<T>. The Authenticate method is passed the RestRequest currently being executed giving you access to every part of the request data (headers, parameters, etc.)

You can find an example of a custom authenticator that fetches and uses an OAuth2 bearer token here.