How to auth against Monzo's API in R

monzo_auth_example.R

library(httr)
library(jsonlite)

# OAuth settings for Monzo:
# https://monzo.com/docs/#authentication
monzo <- oauth_endpoint(
  authorize = "https://auth.getmondo.co.uk/",
  access = "https://api.monzo.com/oauth2/token")

# You need to set up your own Monzo 'app' to play with the API 
# To do so, visit: https://developers.monzo.com/apps/home
# Once you've done so, you need to add the Client ID and secret below
# It's worth noting that Monzo's refresh token approach means you may need to frequently wipe your R's oauth token cache manually
myapp <- oauth_app("monzo", 
                   key = "", # Client ID
                   secret = "") # Client Secret
monzo_token <- oauth2.0_token(monzo, myapp, cache = TRUE) 

# As an example to show it works, we use the API to retrieve an account ID.
# (We just get the first one)
accountRequest <- GET("https://api.monzo.com/accounts", config(token = monzo_token))
accountsJson = fromJSON(content(accountRequest, as = "text"))
accountID = accountsJson$accounts[1, "id"]
accountID