Faraday is an high-level HTTP client library with middleware support, and support for multiple low-level HTTP client libraries. It can be used just by adding it to the Gemfile and running
bundle install, just like RestClient can. Or, a different library can be added to the Gemfile and then used through one of its adapters.
The faraday_middleware library, which was started by Wynn Netherland and has been maintained by Erik Michaels-Ober, contains a bunch of middlewares for authentication, response parsing, and convenient hash objects.
Faraday Stack is a pretty generic yet convenient API client. It encodes JSON, parses XML and JSON, follows redirects, and raises errors. In short, it works like many expect custom API clients to work, yet it can be used anywhere, just by specifying the domain. It doesn’t include authentication, which ships with many API clients, but that can be added easily by looking at the source for the stack and adding authentication from another library into it. It’s better than many custom API clients, so if an API client is the slightest bit frustrating, it may be a good idea to use faraday_stack instead.
I really like Faraday, because it lets me choose which HTTP library I’m going to use, which is different between Ruby and JRuby. I often use Faraday by itself even when a custom API client is available. I also will use it in irb (next time, pry) instead of curl at times.