I’ve got a V8-based pkg — curlconverter — https://github.com/hrbrmstr/curlconverter — for taking “Copy as cURL” links from browser session and automagically turning them into httr calls. I initially made it to help me with SO answers and also to make API pkgs for “hidden” APIs. It has been more widely received than I had expected and I think it may fit in with rOpenSci’s mission.
If folks think this’d be a good candidate for rOpenSci i’ll be glad to start the process of overhauling the docs, R style, etc to get it into shape for a submission.