Authenticating

library(fantasy)

In order to use the restricted part of the API, you must provide valid login details for the FPL website. You can create these by going to https://fantasy.premierleague.com and signing up for free.

There are a few different ways to authenticate and the best option for you will depend on your use case.

Interactively

If you are using RStudio IDE you can simply run authenticate() and some prompts will appear which ask you to fill out your email address and password. Once you have done this, the result will be saved for the remainder of your session only. If you are just playing around with the package and testing it out, this is the easiest way to authenticate.

Non-interactively

If you are not using RStudio IDE you can supply email and password arguments to the authentication function:

authenticate(email = "my@email_address.co.uk",
             password = "mypassword")

Environment variables

While the above method can be useful for those running R interactively outside of RStudio, it is not an ideal way of solving the problem of code that is to be run non-interactively at a later date - e.g. in a shiny app, another package, or as part of a script that is to be shared.

For these use cases, it is better to take advantage of the “FPL_LOGIN” and “FPL_PASSWORD” environment variables. If these are set, they will be used to authenticate before all other options.

You can then set these in your .Renviron file to avoid having to re-enter your credentials every time you use the package. Make sure to add your .Renviron to your .gitignore if you are using Git for your project.

#Sys.setenv("FPL_LOGIN" = "my@email_address.co.uk)
#Sys.setenv("FPL_PASSWORD" = "mypassword")
authenticate()

How it works

The authentication function works by sending a POST request to the FPL API and storing the resulting authentication cookie as an option for the session. This cookie is then used whenever a restricted action is taken.

You can see the cookie by running getOption("FANTASY_COOKIE"). If you unset or remove this, you will need to re-authenticate.

As the authentication cookie is only temporary, you will have to authenticate in every R session you run. However, you can use the Environment Variables method above to avoid having to enter your credentials every time.