What is Katalon Studio?
Katalon Studio is an easy-to-use automation tool for testing APIs, web, and mobile applications. It helps both beginners and experts perform tests quickly.

Setting Up API Test in Katalon Studio

• Download and Install Katalon Studio: Get it from Katalon.
• Create a New Project: Open Katalon, create a new API project.

Example 1: Simple GET Request

• Create a Test Case: Right-click on Test Cases > New Test Case and name it "GetPostsTest".
• Add GET Request: URL: https://jsonplaceholder.typicode.com/posts.
• Verify Response:

import com.kms.katalon.core.webservice.keyword.WSBuiltInKeywords as WS

def response = WS.sendRequest(findTestObject('API Requests/GetPostsRequest'))
WS.verifyResponseStatusCode(response, 200)
WS.verifyElementPropertyValue(response, 'title', 'sunt aut facere repellat')

• This tests if the API returns status 200 and checks the title property.

Example 2: Simple POST Request

• Create a POST Request: URL: https://jsonplaceholder.typicode.com/posts. Body:

{
  "title": "foo",
  "body": "bar",
  "userId": 1
}

• Send and Validate:

def response = WS.sendRequest(findTestObject('API Requests/PostCreateRequest'))
WS.verifyResponseStatusCode(response, 201)
WS.verifyElementPropertyValue(response, 'title', 'foo')

Conclusion
Katalon Studio simplifies API testing by providing an intuitive interface. With just a few steps, you can automate API requests, validate responses, and ensure your application integrates properly.