How To Use Postman Chrome Plugin

Getting Started with Postman Chrome Plugin for API Testing

The Postman Chrome plugin is a powerful tool for API testing that allows you to send requests, analyze responses, and manage your API workflows right from your browser. This guide will walk you through the basics of using the plugin, covering essential features and providing practical examples.

Installing the Postman Chrome Plugin

1. Open the Chrome Web Store: Navigate to the Chrome Web Store in your browser by typing “chrome web store” in the address bar.
2. Search for “Postman”: In the search bar, type “Postman” and press enter.
3. Select “Postman - API Client”: Scroll through the search results and find the Postman plugin, recognizing it by the familiar Postman logo.
4. Click “Add to Chrome”: This button will install the plugin to your browser.
5. Verify the installation: After installation, a notification will appear confirming successful installation. You will find the Postman icon added to your browser’s toolbar.

Building Your First API Request with the Postman Chrome Plugin

1. Launch the Postman Plugin: Click the Postman icon in your browser’s toolbar to open the plugin interface.
2. Create a New Request: Click the “New” button in the top left corner of the window. It looks like a plus sign.
3. Select the HTTP Method: Choose the HTTP method for your request. The most common methods include GET, POST, PUT, DELETE, and PATCH. Click the dropdown arrow next to “GET” to select the appropriate method for your API.
4. Enter the API Endpoint: In the “Enter request URL” field, type the complete URL of the API endpoint you want to test. For example: https://api.example.com/users.
5. Send the Request: Click the “Send” button (it looks like a blue arrow) to send your request to the API.
6. View the Response: The response from the API server will be displayed in the “Response” tab. Here, you can see the status code, headers, and body of the response.

Example: Let’s make a simple GET request to the “users” endpoint of a hypothetical API.

Request URL: https://api.example.com/users

HTTP Method: GET

Response:

Status Code: 200 (OK)
Headers:
Content-Type: application/json
Body:
[
  {
    "id": 1,
    "name": "John Doe",
    "email": "john.doe@example.com"
  },
  {
    "id": 2,
    "name": "Jane Doe",
    "email": "jane.doe@example.com"
  }
]

Adding Parameters to Your Request

For many APIs, you may need to send additional parameters to your request. With the Postman Chrome plugin, you can easily add parameters through the “Params” tab.

1. Access the “Params” tab: Click the “Params” tab located near the “Headers” and “Body” tabs.
2. Input Parameters: Click on ”+ Add param” and type the name of your parameter in the first column and its value in the second column.
3. Send the Request: Click “Send” to issue your request with the added parameters.

Example: Let’s send a GET request to /users with a “userId” parameter to retrieve information on a specific user.

Request URL:  https://api.example.com/users

HTTP Method: GET

Params:
Key: userId
Value: 1

Response:

Status Code: 200 (OK)
Headers:
Content-Type: application/json
Body:
{
  "id": 1,
  "name": "John Doe",
  "email": "john.doe@example.com"
}

Working with Request Headers

Request headers provide additional information about your request, such as authorization details or content type. You can manage headers in the “Headers” tab.

1. Access the “Headers” tab: Click the “Headers” tab to manage request headers.
2. Add or Edit Headers: You can add new headers by clicking ”+ Add header” or modify existing headers by clicking on the edit button.
3. Send the Request: Send your request to see the effect of the headers you added.

Example: Let’s add an “Authorization” header with a token to access a protected API endpoint.

Request URL: https://api.example.com/protected

HTTP Method: GET

Headers:
Key: Authorization
Value: Bearer your_access_token

Response:
Status Code: 200 (OK)
Headers:
Content-Type: application/json
Body:
{
 "message": "Protected resource accessed successfully"
}

Sending a Request Body

For methods like POST, PUT, and PATCH, you can send data in the request body.

1. Access the “Body” Tab: Click the “Body” tab to construct the request body.
2. Choose the Body Format: Select the data format for your body:
   • form-data: For sending simple key-value pairs like form submissions.
   • x-www-form-urlencoded: For sending encoded data in a URL like query parameters.
   • raw: For sending unstructured data in various formats (JSON, XML, or plain text).
   • binary: For uploading files directly.
3. Input Body Data: Enter your data in the appropriate format. For example, for a JSON body, you can paste valid JSON code.
4. Send the Request: Issue your request to send the data to the API.

Example: Send a POST request to users with a new JSON user object.

Request URL: https://api.example.com/users

HTTP Method: POST

Body:
Type: raw
Format: JSON
{
  "name": "Alice Smith",
  "email": "alice.smith@example.com"
}

Response:
Status Code: 201 (Created)
Headers:
Content-Type: application/json
Body:
{
  "id": 3,
  "name": "Alice Smith",
  "email": "alice.smith@example.com"
}

Saving and Managing Requests

To organize your testing efforts, you can save your requests and collections (groupings of requests) within the Postman plugin.

1. Save a Single Request: Click the “Save” button (it looks like a floppy disk) next to the “Send” button and give your request a meaningful name.
2. Create a Collection: Click the “Collections” tab to create a new collection.
3. Add Requests to a Collection: Drag and drop saved requests into your collection.
4. Organize with Folders: You can further group requests within a collection using folders.
5. Run Collections: Collections provide a way to execute a series of requests in sequence.

Beyond the Basics: Harnessing Advanced Functionality

The Postman Chrome plugin offers additional features for more advanced API testing.

• Environment Variables and Tests: Postman lets you define environment variables for storing sensitive information like API keys and configure tests to validate your API responses.

• Authorization: Set up authorization mechanisms for accessing protected APIs, including OAuth, API keys, and basic authentication.

• Mocking: Create mock server responses to simulate API behavior for development or testing without relying on actual backend services.

• Pre-Request Scripts and Tests: Automate pre-request tasks and write assertion-based tests to validate the success of your API calls.

By learning to use the Postman Chrome plugin effectively, you can streamline your API testing process, get comprehensive results, and improve the quality of your APIs.