This guide provides practical examples and advanced concepts for building high-quality REST APIs.

1. JSON (JavaScript Object Notation)

JSON is the standard format for REST APIs. It is lightweight and easy for both humans and machines to read.

Example Response:

{
  "id": 1,
  "title": "Introduction to REST",
  "author": {
    "id": 42,
    "name": "Jane Smith"
  },
  "tags": ["api", "web", "rest"]
}

2. Versioning your API

Always version your API to avoid breaking changes for your users. - Path versioning (Recommended): https://api.example.com/v1/products - Header versioning: Accept: application/vnd.example.v1+json

3. Error Handling

Always return a consistent error object.

{
  "error": "Resource Not Found",
  "message": "The book with ID 999 does not exist in our database.",
  "code": 404
}

4. Pagination

For endpoints that return lists, never return thousands of items at once. Use pagination. - GET /products?page=2&limit=20 - Response should include metadata:

{
  "data": [...],
  "meta": {
    "current_page": 2,
    "total_pages": 50,
    "total_items": 1000
  }
}

5. Security

  • HTTPS: Always use encryption.
  • Authentication: Use JWT (JSON Web Tokens) or API Keys.
  • Rate Limiting: Prevent abuse by limiting requests per minute per user.

6. Documentation

A REST API is only as good as its documentation. - Use OpenAPI (Swagger) for interactive docs (FastAPI does this automatically!). - Provide clear examples for every endpoint.