In this section, we will guide you through the process of creating your first API request using Postman. This is a fundamental skill for anyone looking to perform API testing, as it allows you to interact with APIs and understand how they work.

1. API Request: A request sent to a server to retrieve or modify data.
2. HTTP Methods: The actions you want to perform on the resource (e.g., GET, POST, PUT, DELETE).
3. Request URL: The endpoint where the API is hosted.
4. Headers: Additional information sent with the request, such as content type or authorization tokens.
5. Body: The data sent with the request, typically used with POST or PUT methods.

• Launch the Postman application on your computer.
• If you haven't installed Postman yet, refer to the previous section on Setting Up Postman.

1. Click on the "New" button in the top left corner of the Postman interface.
2. Select "Request" from the dropdown menu.

• Name Your Request: Give your request a meaningful name, such as "First API Request".
• Select a Collection: You can save your request in a collection for better organization. If you don't have a collection yet, you can create one.

1. Choose the HTTP Method: Select the method you want to use from the dropdown (e.g., GET).
2. Enter the Request URL: Type the URL of the API endpoint you want to interact with. For example, you can use a public API like https://jsonplaceholder.typicode.com/posts.

• Click on the "Headers" tab to add any necessary headers. For a basic GET request, headers are often not required.

• Click the "Send" button to execute the request.
• Postman will display the response from the server in the lower section of the interface.

• Status Code: Check the status code to determine if the request was successful (e.g., 200 OK).
• Response Body: View the data returned by the server. This could be in JSON, XML, or another format.
• Headers: Review the response headers for additional information about the response.

Here is a simple example of a GET request to retrieve posts from a public API:

• HTTP Method: GET is used to retrieve data.
• Request URL: The endpoint https://jsonplaceholder.typicode.com/posts is a placeholder API that returns a list of posts.
• Response: You should see a JSON array of posts in the response body.

Task: Create a POST request to add a new post to the same API.

1. HTTP Method: POST
2. Request URL: https://jsonplaceholder.typicode.com/posts
3. Headers: Content-Type: application/json
4. Body:

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

1. Open Postman and create a new request.
2. Set the method to POST and enter the URL.
3. Add a header with Content-Type: application/json.
4. In the Body tab, select "raw" and paste the JSON data.
5. Click "Send" and observe the response.

• Incorrect URL: Ensure the URL is correct and accessible.
• Missing Headers: For POST requests, always set the Content-Type header appropriately.
• Invalid JSON: Ensure the JSON body is correctly formatted.

Congratulations! You've successfully created your first API request using Postman. This foundational skill will be crucial as you progress through more complex API testing scenarios. In the next section, we will delve deeper into understanding the request and response cycle.