RESTful API Best Practices Guide

What is REST?

REST (Representational State Transfer) is an architectural style for designing networked applications. It relies on a stateless, client-server communication protocol, almost always HTTP.

Stateless communication
Resource-based URLs
HTTP methods for operations
JSON for data exchange
Cacheable responses

GET /api/users/123

{
  "id": 123,
  "name": "John Doe",
  "email": "john@example.com"
}

REST Principles

🏗️

Client-Server Architecture

Separation of concerns between client and server, allowing independent evolution of both.

🔄

Stateless

Each request contains all information needed to process it. No client context stored on server.

💾

Cacheable

Responses must define themselves as cacheable or non-cacheable to improve performance.

🎯

Uniform Interface

Standardized way of communicating between client and server using HTTP methods and status codes.

📚

Layered System

Architecture composed of hierarchical layers, each with specific responsibilities.

⚡

Code on Demand

Optional constraint allowing server to extend client functionality by transferring executable code.

HTTP Methods

GET

Retrieve Resources

Used to retrieve data from the server. Should be safe and idempotent.

GET /api/users GET /api/users/123

POST

Create Resources

Used to create new resources on the server. Not idempotent.

POST /api/users POST /api/orders

PUT

Update/Replace Resources

Used to update or replace entire resources. Should be idempotent.

PUT /api/users/123 PUT /api/products/456

PATCH

Partial Updates

Used to apply partial modifications to resources.

PATCH /api/users/123 PATCH /api/settings

DELETE

Remove Resources

Used to delete resources from the server. Should be idempotent.

DELETE /api/users/123 DELETE /api/posts/789

OPTIONS

Get Options

Used to describe communication options for the target resource.

OPTIONS /api/users OPTIONS *

HTTP Status Codes

2xx Success

200 OK - Request successful

201 Created - Resource created successfully

204 No Content - Successful with no response body

4xx Client Error

400 Bad Request - Invalid request syntax

401 Unauthorized - Authentication required

404 Not Found - Resource doesn't exist

5xx Server Error

500 Internal Server Error - Server malfunction

502 Bad Gateway - Invalid response from upstream

503 Service Unavailable - Server temporarily unavailable

Best Practices

🔗 Use Nouns for Resources

✅ Good /users, /products, /orders

❌ Bad /getUsers, /createProduct

📊 Use HTTP Methods for Actions

✅ Good POST /users, DELETE /users/123

❌ Bad POST /users/create, GET /users/delete/123

🏗️ Consistent Naming

✅ Good /users, /user-profiles

❌ Bad /Users, /user_profiles

🔢 Version Your API

✅ Good /api/v1/users, /api/v2/users

❌ Bad /api/users (no versioning)

📄 Use Pagination

✅ Good ?page=1&limit=20

❌ Bad Return all records without pagination

🔍 Support Filtering

✅ Good ?status=active&role=admin

❌ Bad No filtering options provided

API Examples

Get All Users

GET /api/v1/users?page=1&limit=10

{
  "data": [
    {
      "id": 1,
      "name": "John Doe",
      "email": "john@example.com",
      "created_at": "2023-01-15T10:30:00Z"
    }
  ],
  "pagination": {
    "page": 1,
    "limit": 10,
    "total": 150,
    "pages": 15
  }
}

Create User

POST /api/v1/users

{
  "name": "Jane Smith",
  "email": "jane@example.com",
  "password": "securepassword123"
}

Get Product by ID

GET /api/v1/products/123

{
  "id": 123,
  "name": "Wireless Headphones",
  "price": 99.99,
  "category": "electronics",
  "in_stock": true
}

Create Order

POST /api/v1/orders

{
  "user_id": 1,
  "items": [
    {
      "product_id": 123,
      "quantity": 2,
      "price": 99.99
    }
  ],
  "total": 199.98
}