How to: API Builder and Discovery
* [ActiveModel::Serializers](https://github.com/rails-api/active_model_serializers) - JSON serialization of objects.
* [Acts_As_Api](https://github.com/fabrik42/acts_as_api) - Easy And Fun, in creating XML/JSON responses in Rails 3,4,5 and 6.
* [Alba](https://github.com/okuramasafumi/alba) - A JSON serializer for Ruby, JRuby and TruffleRuby.
* [Blanket](https://github.com/inf0rmer/blanket) - A dead simple API wrapper.
* [Blueprinter](https://github.com/procore/blueprinter) - Simple, Fast, and Declarative Serialization Library for Ruby.
* [cache_crispies](https://github.com/codenoble/cache-crispies) - Speedy Rails JSON serialization with built-in caching.
* [Crepe](https://github.com/crepe/crepe) - The thin API stack.
* [EasyTalk](https://github.com/sergiobayona/easy_talk) - Define structured data models with a DSL that generates JSON Schema and ActiveModel validations from a single source of truth.
* [Grape](http://www.ruby-grape.org) - An opinionated micro-framework for creating REST-like APIs in Ruby.
* [Her](https://github.com/remiprev/her) - an ORM that maps REST resources to Ruby objects. Designed to build applications that are powered by a RESTful API instead of a database.
* [jbuilder](https://github.com/rails/jbuilder) - Create JSON structures via a Builder-style DSL.
* [jsonapi-rb](http://jsonapi-rb.org) – Efficient and convenient JSON API (de)serialization library.
* [jsonapi-serializer](https://github.com/jsonapi-serializer/jsonapi-serializer) - A fast JSON:API serializer for Ruby Objects.
* [JSONAPI::Resources](https://github.com/cerebris/jsonapi-resources) - JSONAPI::Resources, or "JR", provides a framework for developing a server that complies with the JSON API specification.
* [JSONAPI::Utils](https://github.com/tiagopog/jsonapi-utils) - JSONAPI::Utils is built on top of JSONAPI::Resources taking advantage of its resource-driven style and bringing an easy way to build modern JSON APIs with no or less learning curve.
* [Jsonite](https://github.com/crepe/jsonite) - A tiny, HAL-compliant JSON presenter for your APIs.
* [Pliny](https://github.com/interagent/pliny) - Opinionated template Sinatra app for writing excellent APIs in Ruby.
* [rabl](https://github.com/nesquena/rabl) - General ruby templating with json, bson, xml, plist and msgpack support.
* [Roar](https://github.com/apotonick/roar) - Resource-Oriented Architectures in Ruby.
* [Spyke](https://github.com/balvig/spyke) - Interact with REST services in an ActiveRecord-like manner.
* [Version Cake](https://github.com/bwillis/versioncake) - An unobtrusive way to version APIs in your Rails app.
* [versionist](https://github.com/bploetz/versionist) - A plugin for versioning Rails based RESTful APIs.