Shiny Token Auth makes it easy to authenticate between a remote server and a Shiny server application. This can be useful in situations where a user authenticates through a web-app, and you want to embed a Shiny application in an iframe in your website, but otherwise lock-down someone directly accessing the Shiny application.

Your remote application should generate a token each time it loads the Shiny application. That token should then be appended to the Shiny application url using the parameter t. For example:

http://some-shiny-app.example?t=some_unique_token

Shiny Token Auth will then check the passed t argument, in this case some_unique_token against the remote server by sending it back to the remote server at a specified callback url (covered in the next section on configuring your settings).

If the token is valid, then the Shiny Token Auth method isValidToken returns TRUE. Otherwise, it returns FALSE.

The settings.json file is a simple JSON file with two keys.

• check_token_url - This is the URL the token passed to your Shiny server should check against to make sure the token is valid.
• success_value - This is the value your remote application will provide if authentication is succesful. For example, your server might return "200" or "OK".

Once you have configured your settings.json and setup your remote application to generate and check the validity of tokens, you can Shiny Token Auth by invoking the isValidToken method.

isValidToken takes the full URL used to access your Shiny application as an argument. The method then checks whether the passed token, demarked as t in the URL paremeters, is valid.

In your Shiny application, you can wrap isValidToken in a reactive method and assign it to a variable. For example:

shinyServer(function(input, output, session) {
  	# determine if the user is authenticated
  	isAuth <- reactive({ isValidToken(session$clientData$url_search) })
  	
  	# the rest of your code below
}

You can now use the value of isAuth (which is either TRUE or FALSE), to determine whether your user is authenticated or not. If a user is not authenticated, you could cut off access to the datasource, or change the UI displayed in your ui.R file.

Shiny Token Auth depends on the following libraries:

• shiny
• jsonlite
• curl