Resource expansion (embed related data) in Rest API

Introduction

Resource expansion helps you get related information in one request. It saves time and makes your app faster.

When you want to show a user and their posts together.

When you need product details along with its reviews in one response.

When you want to load an order and its items at the same time.

When you want to reduce the number of API calls to improve speed.

Syntax

Rest API

GET /resource?expand=related_resource

The expand query parameter tells the API to include related data.

You can often expand multiple related resources by separating them with commas.

Examples

This request gets users and includes their profile details inside each user.

Rest API

GET /users?expand=profile

This request gets orders and includes both the items in the order and the customer info.

Rest API

GET /orders?expand=items,customer

Sample Program

This program fetches orders with their items and customer info in one request. It then prints each order's details clearly.

Rest API

import requests

# URL of the API endpoint
url = 'https://api.example.com/orders?expand=items,customer'

# Send GET request
response = requests.get(url)

# Check if request was successful
if response.status_code == 200:
    data = response.json()
    for order in data['orders']:
        print(f"Order ID: {order['id']}")
        print(f"Customer Name: {order['customer']['name']}")
        print("Items:")
        for item in order['items']:
            print(f" - {item['product_name']} x{item['quantity']}")
        print()
else:
    print(f"Failed to get data: {response.status_code}")

Important Notes

Not all APIs support resource expansion; check the API docs first.

Expanding too many resources can make the response large and slow.

Use expansion wisely to balance speed and data size.

Summary

Resource expansion lets you get related data in one API call.

Use the expand parameter with resource names to embed data.

This reduces the number of requests and speeds up your app.