How to create a RESTful API using CodeIgniter?

Creating a RESTful API using CodeIgniter, a lightweight and user-friendly PHP framework, can be accomplished with a straightforward approach. Here’s a step-by-step guide on how to create a RESTful API using CodeIgniter:


  1. Install CodeIgniter:

   First, ensure that CodeIgniter is installed on your system. You can download the latest version from the official website or use Composer to install it.


  1. Configure Routes:

   CodeIgniter manages routes in the `application/config/routes.php` file. Define routes for your API endpoints using a simple and intuitive syntax:

$route['api/resource'] = 'ApiController/resource';
  1. Create a Controller:

   Generate a controller to handle API requests. CodeIgniter makes this easy with its CLI tool. Open your terminal and navigate to your project’s root directory:

php spark make:controller ApiController
  1. Implement Controller Methods:

   In the generated controller, define methods to handle different API endpoints. For example, you can create an `index` method to fetch and return a list of resources:

public function resource()
    $data = $this->resourceModel->getAllResources();
    return $this->response->setJSON($data);
  1. Database Models:

   Create models for your database tables and configure them to interact with your database using CodeIgniter’s query builder or an ORM like Eloquent.


  1. Validation:

   Ensure data integrity by implementing validation rules using CodeIgniter’s form validation library.


  1. Serialization and Deserialization:

   Serialize data to JSON format for responses and deserialize JSON data into PHP objects for requests.


  1. Authentication and Authorization:

   Implement authentication and authorization logic as per your API’s requirements, such as API tokens or OAuth2.


  1. Testing:

   CodeIgniter supports unit testing, so write tests to ensure the functionality of your API endpoints.


  1. API Documentation:

    Document your API endpoints for developers to understand how to use them efficiently.


  1. Deployment:

    Deploy your CodeIgniter-based RESTful API to a web server or cloud hosting platform.


CodeIgniter’s simplicity and a small learning curve make it suitable for quickly building RESTful APIs. By following these steps and utilizing CodeIgniter’s built-in features and libraries, you can develop a robust and functional API to serve your application’s needs effectively.


Previously at
Flag Argentina
time icon
Full Stack Engineer with extensive experience in PHP development. Over 11 years of experience working with PHP, creating innovative solutions for various web applications and platforms.