Designing RESTful APIs
Plan and structure RESTful API endpoints, methods, and data models suitable for edge deployment.
Designing RESTful APIs is a free Edge Computing with Cloudflare Workers & Deno lesson on CoddyKit — lesson 1 of 3. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Edge Computing with Cloudflare Workers & Deno learning path, one of 3 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Intro to RESTful APIs
Welcome! In this lesson, you'll learn about RESTful APIs, a fundamental way to design web services. REST stands for Representational State Transfer.
Think of an API as a menu in a restaurant. You make a request (order food), and the kitchen (server) sends back a response (your meal). REST defines a set of rules for how this communication should happen over the internet.
Core REST Principles
RESTful APIs are built around a few core ideas:
- Resources: Everything is a 'resource' (e.g., a user, a product).
- Unique URIs: Each resource has a unique address (a URL or URI).
- Standard Methods: HTTP methods (GET, POST, PUT, DELETE) are used to perform actions on resources.
- Statelessness: Each request from a client to a server must contain all the information needed to understand the request. The server doesn't store client 'session' state between requests.
Resources Are Nouns
When designing your API, think about the 'things' your application manages. These 'things' are your resources.
For example, if you're building an e-commerce API, your resources might include:
/products/users/orders/categories
Notice how these are all plural nouns. This is a common and recommended practice in RESTful design.
HTTP Methods: The Verbs
HTTP methods tell the server what kind of action you want to perform on a resource. They are like verbs in a sentence:
- GET: Retrieve data (e.g., get a product, get a list of users).
- POST: Create new data (e.g., create a new user, add a new product).
- PUT: Update existing data (replaces an entire resource).
- PATCH: Partially update existing data (updates specific fields of a resource).
- DELETE: Remove data (e.g., delete a product).
GET: Fetching Data Example
The GET method is used to request data from a specified resource. It should never have side effects (i.e., it shouldn't change data on the server).
Try running this simple Deno server. Then open your browser to http://localhost:8000/products to see the output.
import { serve } from "https://deno.land/std/http/server.ts";
serve(async (req) => {
const url = new URL(req.url);
if (req.method === "GET" && url.pathname === "/products") {
const products = [
{ id: 1, name: "Wireless Mouse", price: 25.99 },
{ id: 2, name: "Mechanical Keyboard", price: 79.99 }
];
return new Response(JSON.stringify(products), {
headers: { "Content-Type": "application/json" }
});
}
return new Response("Not Found", { status: 404 });
}, { port: 8000 });
console.log("Server running on http://localhost:8000");POST: Creating Data Example
The POST method is used to submit an entity to the specified resource, often causing a change in state or the creation of a new resource.
This example shows how a Deno server can handle a POST request to create a new product. You would typically send JSON data in the request body.
import { serve } from "https://deno.land/std/http/server.ts";
serve(async (req) => {
const url = new URL(req.url);
if (req.method === "POST" && url.pathname === "/products") {
try {
const newProduct = await req.json();
// In a real application, you'd save newProduct to a database.
// For this example, we'll just log it and return a mock ID.
console.log("Received new product:", newProduct);
return new Response(JSON.stringify({ ...newProduct, id: 3 }), {
status: 201, // 201 Created
headers: { "Content-Type": "application/json" }
});
} catch (e) {
return new Response("Invalid JSON payload", { status: 400 });
}
}
return new Response("Method Not Allowed", { status: 405 });
}, { port: 8000 });
console.log("Server running on http://localhost:8000");Designing Endpoint Paths
Clear and consistent endpoint paths (URIs) are crucial for a good API. Here are some best practices:
- Use plural nouns:
/users, not/user. - Avoid verbs in paths:
/productsis good,/getProductsis not. The HTTP method implies the action. - Nesting for relationships: For related resources, use nesting. E.g.,
/users/{id}/ordersto get orders for a specific user. - Use path parameters for specific resources:
/products/{id}to refer to a single product.
Data Models & Payloads
The data you send to and receive from your API is called a payload. In modern RESTful APIs, JSON (JavaScript Object Notation) is the standard format.
A data model defines the structure of this JSON. For example, a 'product' data model might look like this:
{
"id": 123,
"name": "Example Product",
"description": "A great item.",
"price": 19.99
}Consistency in your data models makes your API predictable and easier to use.
RESTful APIs at the Edge
RESTful API design is particularly well-suited for edge computing environments like Cloudflare Workers:
- Statelessness: Edge functions are often short-lived and don't maintain state, aligning perfectly with REST's stateless principle.
- Caching: GET requests are easily cacheable by CDNs, which is a core benefit of edge computing for reducing latency.
- Distributed Nature: REST's clear separation of concerns and uniform interface makes it easier to distribute logic across many edge locations.
API Design Check
You're building an API for a blog. You need to retrieve a list of all blog posts. Which of the following API endpoint designs and HTTP methods is the most RESTful?
Recap: RESTful API Design
Great job! You've learned the fundamentals of designing RESTful APIs:
- APIs use resources (nouns) and HTTP methods (verbs) for communication.
- Common methods are GET (retrieve), POST (create), PUT/PATCH (update), and DELETE (remove).
- Endpoint paths should be clear, using plural nouns and avoiding verbs.
- JSON is the standard format for data payloads.
- REST's principles make it an excellent choice for edge computing due to statelessness and cacheability.
Next, we'll dive into input validation and security for your edge APIs!
Frequently asked questions
Is the “Designing RESTful APIs” lesson free?
Yes — the full text of “Designing RESTful APIs” is free to read here on the web, and the Edge Computing with Cloudflare Workers & Deno course includes 3 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Edge Computing with Cloudflare Workers & Deno course, upgrade to CoddyKit PRO.
What will I learn in “Designing RESTful APIs”?
Plan and structure RESTful API endpoints, methods, and data models suitable for edge deployment. You practise Edge Computing with Cloudflare Workers & Deno with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Edge Computing with Cloudflare Workers & Deno?
No prior experience is required. Edge Computing with Cloudflare Workers & Deno on CoddyKit is structured for beginners through advanced learners; this is — lesson 1 of 3, so you can start here or from the beginning and move at your own pace.
How long does the “Designing RESTful APIs” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Edge Computing with Cloudflare Workers & Deno lesson?
Yes. Every Edge Computing with Cloudflare Workers & Deno lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Designing RESTful APIs
- Routing & Middleware
- Validation & Error Handling