Build a RESTful API in PHP Without a Framework

#php #beginners #webdev #programming

APIs allow software systems to talk to each other. A RESTful API follows a set of rules for structuring requests and responses. In this tutorial, you’ll learn how to build a simple REST API using plain PHP.

What Is a RESTful API?
Project Setup
Directory Structure
Create the .htaccess File
Routing Requests
Build the Controller
Handle API Methods (GET, POST, PUT, DELETE)
Return JSON Responses
Test Your API
Conclusion

What Is a RESTful API?

REST stands for Representational State Transfer. A RESTful API uses standard HTTP methods to perform operations:

GET – fetch data
POST – add new data
PUT – update existing data
DELETE – remove data

Each request must return a structured response, usually in JSON format.

Project Setup

Create a new folder for the project:

mkdir php-rest-api
cd php-rest-api

You need:

PHP 7.4+ (or 8.x)
Apache with mod_rewrite enabled
A tool like Postman for testing

Directory Structure

Create this structure:

php-rest-api/
├── api/
│   └── index.php
├── .htaccess
└── data.json

index.php: main API logic
data.json: mock database
.htaccess: rewrite rules for clean URLs

Create the .htaccess File

Enable clean URLs and route all requests to index.php.

# .htaccess
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^ api/index.php [QSA,L]
Make sure AllowOverride All is enabled in your Apache config.

Routing Requests

In api/index.php, route requests by URL and method.

<?php

header("Content-Type: application/json");

$method = $_SERVER['REQUEST_METHOD'];
$request = explode("/", trim($_SERVER['PATH_INFO'] ?? '', "/"));

$resource = $request[0] ?? null;
$id = $request[1] ?? null;

require_once 'controller.php';

handleRequest($method, $resource, $id);

Build the Controller

Create a controller.php file inside api/.

<?php

function handleRequest($method, $resource, $id) {
    if ($resource !== 'items') {
        http_response_code(404);
        echo json_encode(["error" => "Resource not found"]);
        return;
    }

    $data = json_decode(file_get_contents(__DIR__ . '/../data.json'), true);

    switch ($method) {
        case 'GET':
            if ($id === null) {
                echo json_encode($data);
            } else {
                $item = $data[$id] ?? null;
                if ($item) {
                    echo json_encode($item);
                } else {
                    http_response_code(404);
                    echo json_encode(["error" => "Item not found"]);
                }
            }
            break;

        case 'POST':
            $input = json_decode(file_get_contents("php://input"), true);
            $id = uniqid();
            $data[$id] = $input;
            file_put_contents(__DIR__ . '/../data.json', json_encode($data, JSON_PRETTY_PRINT));
            http_response_code(201);
            echo json_encode(["id" => $id]);
            break;

        case 'PUT':
            if ($id === null || !isset($data[$id])) {
                http_response_code(404);
                echo json_encode(["error" => "Item not found"]);
                return;
            }
            $input = json_decode(file_get_contents("php://input"), true);
            $data[$id] = $input;
            file_put_contents(__DIR__ . '/../data.json', json_encode($data, JSON_PRETTY_PRINT));
            echo json_encode(["success" => true]);
            break;

        case 'DELETE':
            if ($id === null || !isset($data[$id])) {
                http_response_code(404);
                echo json_encode(["error" => "Item not found"]);
                return;
            }
            unset($data[$id]);
            file_put_contents(__DIR__ . '/../data.json', json_encode($data, JSON_PRETTY_PRINT));
            echo json_encode(["success" => true]);
            break;

        default:
            http_response_code(405);
            echo json_encode(["error" => "Method not allowed"]);
    }
}

Handle API Methods (GET, POST, PUT, DELETE)

Use tools like Postman or curl:
GET All Items

GET /items

GET Single Item

GET /items/{id}

POST New Item

POST /items
Content-Type: application/json

{
  "name": "New Item",
  "price": 10
}

PUT Update Item

PUT /items/{id}
Content-Type: application/json

{
  "name": "Updated Item",
  "price": 20
}

DELETE Item

DELETE /items/{id}

Return JSON Responses

The API uses header("Content-Type: application/json") and echo json_encode(...) to return data in a machine-readable format.

Test Your API

You can test it using:

Postman: GUI tool for API testing
curl: command-line tool
JavaScript fetch() or Axios in the browser

Conclusion

You just built a fully working RESTful API in PHP. You handled routing, methods, and JSON responses—all without a framework. This is great for learning or small-scale projects.

Next steps: