Working Yahoo OAuth2.0 OOB flow

httr_yahoo_oauth2_oob.R

# Requires httr fork available here:
# https://github.com/ctrombley/httr

library(httr)
library(httpuv)

endpoint <- oauth_endpoint("get_request_token", "request_auth", "get_token",
                           base_url = "https://api.login.yahoo.com/oauth2")
                           
app <- oauth_app("yahoo",
                 key = "YOUR_CLIENT_ID",
                 secret = "YOUR_SECRET",
                 redirect_uri = "oob")
                 
token <- oauth2.0_token(endpoint, app, use_oob = TRUE, as_header = TRUE,
                        use_basic_auth = TRUE, cache = TRUE)

config <-  httr::config(token = token)

teamId <- "YOUR_TEAM_ID"
url <- sprintf("https://fantasysports.yahooapis.com/fantasy/v2/team/%s?response=json", teamId)
res <- GET(url, config)
teamRoster <- content(res)
print(teamRoster)