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How to Build an API-Only Application in Ruby on Rails

by | Mar 2, 2023 | API, Applications | 0 comments

Ruby on Rails is a powerful web development framework that provides a lot of useful features out of the box. One of these features is the ability to build API-only applications, which are web applications that only provide an API for other applications to consume, rather than a web-based user interface. In this blog post, we’ll walk through the steps to build an API-only application in Ruby on Rails.

Step 1: Create a New Rails Application

The first step is to create a new Ruby on Rails application with the –api flag, which tells Rails to generate an API-only application. Open up a terminal window and run the following command:

$ rails new my_api --api

This will generate a new Rails application called “my_api” with the –api flag.

Step 2: Create a Controller

Next, we need to create a controller that will handle incoming requests to our API. Run the following command in your terminal:

$ rails generate controller api/v1/my_controller

This will generate a new controller called “MyController” in the “api/v1” namespace.

Step 3: Define Your API Routes

Now that we have a controller, we need to define our API routes so that incoming requests are directed to the correct controller action. Open up the “config/routes.rb” file in your Rails application and add the following code:

namespace :api do
  namespace :v1 do
    resources :my_controller

This will define a namespace for our API called “api/v1” and a resource for our “MyController” controller. The “resources” method generates RESTful routes for the controller actions.

Step 4: Implement Your Controller Actions

With our API routes defined, we can now implement our controller actions. Open up the “app/controllers/api/v1/my_controller.rb” file and add the following code:

class Api::V1::MyController < ApplicationController
  def index
    render json: { message: "Hello, World!" }

This code defines an “index” action that simply returns a JSON response with a “message” key and the value “Hello, World!”.

Step 5: Test Your API

With our API routes and controller actions defined, we can now test our API. Run the following command in your terminal to start the Rails server:

$ rails server

Now, open up a web browser and navigate to “http://localhost:3000/api/v1/my_controller”. You should see a JSON response with the message “Hello, World!”.

Congratulations, you’ve successfully built an API-only application in Ruby on Rails! This is just the beginning of what you can do with Rails, so keep exploring and building amazing applications.

Final Thoughts

Building an API-only application in Ruby on Rails is a great way to create lightweight, high-performance web applications. With the steps outlined in this blog post, you can quickly and easily build your own API and start consuming it from other applications. Remember to always test your API thoroughly and follow best practices for security and performance. Happy coding!

Kirk Makse

Author: Kirk Makse

Greetings, my name is Kirk. I’m the creator of Rails Zone and a passionate Ruby on Rails developer. During my free time, I develop helpful tools and tutorials that aid fellow Ruby on Rails developers in creating applications with improved efficiency and speed.