httr
httr: a friendly http package for R
...Automatic connection sharing across requests to the same website (by default, curl handles are managed automatically), cookies are maintained across requests, and an up-to-date root-level SSL certificate store is used. Requests return a standard reponse object that captures the http status line, headers and body, along with other useful information. Support for OAuth 1.0 and 2.0 with oauth1.0_token() and oauth2.0_token(). The demo directory has eight OAuth demos: four for 1.0 (twitter, vimeo, withings and yahoo) and four for 2.0 (facebook, github, google, linkedin). ...