Skip to content
Postman API Testing Tips

How To Use Curl On Postman

API Testing Blog

How to Integrate cURL with Postman for Enhanced API Testing

Postman is a powerful tool for API testing, but sometimes you might need to leverage the raw power of cURL for specific requests or scenarios. This guide explains how to integrate cURL commands within Postman’s environment for more flexibility and control.

Understanding the Synergy of cURL and Postman

cURL is a command-line tool that allows you to transfer data using various protocols, including HTTP. It’s known for its simplicity and wide range of features, making it ideal for testing APIs directly from the command line. While Postman offers a user-friendly interface, cURL shines when you need:

  • Precise Control: cURL allows you to specify headers, parameters, and request bodies with exact precision.
  • Scripting and Automation: Use cURL in scripts to automate API tests, making your testing workflow more efficient.
  • Complex Scenarios: cURL is perfect for handling complex requests like file uploads, multi-part forms, or custom authentication schemes.

Harnessing the Power of cURL Within Postman

Postman excels in organizing and documenting your API tests, while cURL enhances your testing capabilities. Let’s explore how to use cURL effectively within the Postman environment:

1. Utilizing the cURL Request Runner

Postman’s “cURL Request Runner” is a built-in feature that lets you directly paste cURL commands and execute them within the Postman environment.

Step 1: Open your Postman workspace and create a new request.

Step 2: Click on the “Code” tab at the top of the request window.

Step 3: Choose “cURL” from the dropdown menu.

Step 4: Paste your cURL command directly into the code editor.

Step 5: Click the “Send” button to execute the cURL request.

Example:

curl --request GET \
--url 'https://api.example.com/users' \
--header 'Authorization: Bearer your_api_token'

This code will send a GET request to the specified endpoint, including an authorization header. The response will be displayed in the Postman response window, just like any other request.

2. Generating cURL Commands from Postman

You can also use Postman to generate cURL commands from existing requests, simplifying the process of creating commands:

Step 1: Make a request within Postman using the desired parameters and headers.

Step 2: Go to the “Code” tab again.

Step 3: Select “cURL” from the dropdown menu.

Step 4: The code editor will automatically generate a cURL command mirroring your Postman request. You can copy this command for use in scripts or command lines.

Example cURL command generated from a Postman request:

curl --request POST \
--url 'https://api.example.com/products' \
--header 'Content-Type: application/json' \
--data '{ "name": "Product Name", "price": 100 }'

3. Using cURL Snippets for Advanced Tests

cURL snippets allow you to execute custom cURL commands within the “Tests” tab of a Postman request. This enables you to integrate complex cURL logic into your existing tests.

Step 1: Navigate to the “Tests” tab of your Postman request.

Step 2: Add a new test using the “Add Test” option.

Step 3: Use the pm.sendRequest function to execute your cURL command within the test.

Example:

pm.sendRequest(
  'curl --request GET --url https://api.example.com/weather?city=London',
  (err, res) => {
    if (err) {
      console.log("Error: ", err);
      pm.test("cURL Request Failed", () => {
        console.log("cURL request failed");
        pm.expect(err).to.be.null;
      });
    } else {
      pm.test("cURL Status Code is 200", () => {
        pm.expect(res.code).to.be.equal(200);
      });
    }
  }
);

In this example, we use pm.sendRequest to execute a cURL command that fetches weather data for London. Then, we use Postman’s built-in test assertions to verify the response status code.

Benefits of Integrating cURL and Postman

By combining Postman’s ease of use with cURL’s raw power, you gain a potent API testing approach:

  • Increased Flexibility: Handle complex scenarios and adapt to unique API requirements.
  • Improved Control: Gain precise control over headers, parameters, and request bodies.
  • Enhanced Automation: Automate complex testing tasks for increased efficiency.
  • Simplified Scripting: Use cURL directly within Postman’s test environment.
  • Powerful Debugging: Visualize and examine your requests and responses.

Conclusion

Integrating cURL into your Postman workflow empowers you to craft robust and versatile API tests. It provides greater flexibility and allows you to leverage the vast capabilities of both tools. Remember to prioritize clear documentation of your cURL commands within Postman to ensure maintainability and collaboration.

API Testing Blog