Cucumber is not an API automation tool, but it works well with other API automation tools.

Using API’s for your automation, can make your tests faster and less flaky than going through the UI. In general, API’s change less frequently than the UI; keeping your automation up to date for longer.

API Automation Tools for JVM

RestAssured

RestAssured is an API automation tool for Java.

You can use RestAssured in your step definitions to make API calls and verify responses. For more information see the official website.

API Automation Tools for JavaScript

PactumJS

PactumJS is a REST API Testing Tool for all levels in a Test Pyramid.

For more information see the official docs and boilerplate code.

API Automation Tools for Ruby

REST Client

REST Client is a simple HTTP and REST client for Ruby.

HTTParty

HTTParty can be used to make HTTP calls.

For more information, see the HTTParty docs.

Net::HTTP

Net::HTTP is an HTTP client API for Ruby.

Faraday

Faraday is a HTTP client library for Ruby.

RubyMine

RubyMine is a Ruby and Rails IDE providing a range of developer tools for Ruby.

RubyMine can be used to test RESTful Web Services.

curb

curb provides Ruby-language bindings for the libcurl(3), a fully-featured client-side URL transfer library.

Typhoeus

Typhoeus is a Ruby tool that wraps libcurl in order to make fast and reliable requests.

For more information, see the Typhoeus Ruby docs.