Your First API Request

Time to send your first real API request! We'll use a free mock e-commerce API to practice.

The Test API

We'll use FakeStoreAPI - a free API that simulates an e-commerce backend:

Available endpoints:

• /products - Product catalog
• /carts - Shopping carts
• /users - User accounts

---

Sending a GET Request

Let's fetch all products:

Step 1: Create the Request

• Click + for a new request tab
• Select GET from the dropdown
• Enter URL: https://fakestoreapi.com/products
• Click Send

Step 2: Examine the Response

You should see something like:

[
  {
    "id": 1,
    "title": "Fjallraven - Foldsack No. 1 Backpack",
    "price": 109.95,
    "description": "Your perfect pack for everyday use...",
    "category": "men's clothing",
    "image": "https://fakestoreapi.com/img/81fPKd-2AYL._AC_SL1500_.jpg",
    "rating": {
      "rate": 3.9,
      "count": 120
    }
  },
  {
    "id": 2,
    "title": "Mens Casual Premium Slim Fit T-Shirts",
    "price": 22.3,
    ...
  }
]

---

Understanding the Response

Look at the response panel:

Status Code

Status: 200 OK

Common status codes:

Response Time

Time: 245 ms

This tells you how long the API took to respond. For e-commerce:

• < 200ms = Excellent
• 200-500ms = Good
• 500ms-1s = Acceptable
• > 1s = Needs optimization

Response Size

Size: 5.2 KB

Larger responses take longer to download - important for mobile users.

---

Fetching a Single Product

Let's get details for product ID 1:

• New request tab
• GET https://fakestoreapi.com/products/1
• Click Send

Response:

{
  "id": 1,
  "title": "Fjallraven - Foldsack No. 1 Backpack",
  "price": 109.95,
  "description": "Your perfect pack for everyday use and target item",
  "category": "men's clothing",
  "image": "https://fakestoreapi.com/img/81fPKd-2AYL._AC_SL1500_.jpg",
  "rating": {
    "rate": 3.9,
    "count": 120
  }
}

Notice: Single object {} vs array [] for multiple products.

---

Request Components

Every API request has these parts:

┌─────────────────────────────────────────────────────┐
│ METHOD │ URL                                        │
├────────┴────────────────────────────────────────────┤
│ GET      https://fakestoreapi.com/products/1        │
├─────────────────────────────────────────────────────┤
│ HEADERS                                             │
│ Content-Type: application/json                      │
│ Authorization: Bearer token123                      │
├─────────────────────────────────────────────────────┤
│ BODY (for POST/PUT)                                 │
│ { "productId": 1, "quantity": 2 }                   │
└─────────────────────────────────────────────────────┘

---

Response Components

┌─────────────────────────────────────────────────────┐
│ STATUS CODE                                         │
│ 200 OK                                              │
├─────────────────────────────────────────────────────┤
│ HEADERS                                             │
│ Content-Type: application/json                      │
│ X-RateLimit-Remaining: 99                           │
├─────────────────────────────────────────────────────┤
│ BODY                                                │
│ { "id": 1, "title": "Backpack", "price": 109.95 }   │
└─────────────────────────────────────────────────────┘

Click the Headers tab in the response section to see response headers.

---

Saving Your Request

Don't lose your work! Save requests to your collection:

• Click Save (or Ctrl/Cmd + S)
• Name it: Get All Products
• Select folder: Products
• Click Save

Now it appears in your sidebar:

📁 Shop API
  📁 Products
     GET Get All Products  ← Saved!

---

Practice Exercises

Exercise 1: Get Limited Products

Fetch only the first 5 products:

GET https://fakestoreapi.com/products?limit=5

Save as: Get Products (Limit 5)

Exercise 2: Get Products by Category

Fetch only electronics:

GET https://fakestoreapi.com/products/category/electronics

Save as: Get Electronics

Exercise 3: Get a Cart

Fetch cart with ID 1:

GET https://fakestoreapi.com/carts/1

Response shows cart with product IDs and quantities:

{
  "id": 1,
  "userId": 1,
  "date": "2020-03-02T00:00:00.000Z",
  "products": [
    { "productId": 1, "quantity": 4 },
    { "productId": 2, "quantity": 1 }
  ]
}

Save as: Get Cart by ID in the Cart folder.

---

Common Mistakes

1. Forgetting the Protocol

❌ fakestoreapi.com/products

✅ https://fakestoreapi.com/products

2. Trailing Slashes

Some APIs are sensitive:

• https://api.example.com/products ✅
• https://api.example.com/products/ ❌ (might fail)

3. Case Sensitivity

URLs can be case-sensitive:

• /Products might differ from /products

---

What's in the Response Headers?

Click Headers tab in response:

---

Key Takeaways

• GET requests fetch data without modifying it
• Status codes tell you if the request succeeded
• Response time indicates API performance
• Always save requests to your collection
• URL structure: protocol://domain/path?query

Next up: HTTP Methods - learn POST, PUT, DELETE for full CRUD operations!