Building RESTful APIs: A Complete Guide

REST (Representational State Transfer) is an architectural style for building web services. A well-designed RESTful API is intuitive, consistent, and easy to use.

REST Principles

1. Stateless

Each request must contain all the information needed to process it.

2. Client-Server Architecture

Clear separation between client and server responsibilities.

3. Cacheable

Responses should be cacheable when appropriate.

4. Uniform Interface

Consistent naming conventions and resource identification.

HTTP Methods

Use appropriate HTTP methods for different operations:

• GET: Retrieve resources
• POST: Create new resources
• PUT: Update entire resources
• PATCH: Partial updates
• DELETE: Remove resources

URL Design

Design clean, intuitive URLs:

GET    /api/users           # Get all users
GET    /api/users/123       # Get specific user
POST   /api/users           # Create new user
PUT    /api/users/123       # Update user
DELETE /api/users/123       # Delete user

Status Codes

Use appropriate HTTP status codes:

• 200: Success
• 201: Created
• 400: Bad Request
• 401: Unauthorized
• 404: Not Found
• 500: Internal Server Error

Example Implementation

// Express.js example
app.get("/api/users/:id", async (req, res) => {
  try {
    const user = await User.findById(req.params.id);
    if (!user) {
      return res.status(404).json({ error: "User not found" });
    }
    res.json(user);
  } catch (error) {
    res.status(500).json({ error: "Internal server error" });
  }
});

Following REST principles creates APIs that are easy to understand and maintain!