Skip to content
Postman API Testing Tips

Does Postman Use Origin Headers

API Testing Blog

Understanding Origin Headers in API Testing

When testing APIs, understanding and utilizing headers is crucial. One important header is the Origin header, which provides information about the source of the request. Here’s a comprehensive guide to how Postman handles Origin headers and why it matters in API testing.

What is the Origin Header?

The Origin header is part of the HTTP request that indicates the domain, protocol, and port number of the website or application that initiated the request. It’s used for security purposes, particularly with Cross-Origin Resource Sharing (CORS).

Example:

Origin: https://www.example.com

Does Postman Use Origin Headers?

Yes, Postman can send and receive Origin headers. By default, Postman will automatically include an Origin header in requests if it detects that you’re making a cross-origin request. This means if your request targets a different domain than the one you’re sending it from, Postman will automatically include the Origin header with your domain information.

How to Manage Origin Headers in Postman

You have several ways to manage Origin headers in Postman, offering you control over how requests are sent:

1. Automatic Origin Header Handling

As mentioned, Postman usually handles the Origin header automatically. If you’re making cross-origin requests, Postman will add the Origin header with your current domain information.

2. Manually Setting the Origin Header

You can manually set the Origin header in Postman for specific scenarios. Here’s how:

  1. Open your Postman request: Go to the request you want to modify.
  2. Navigate to the Headers tab: Click on the “Headers” tab.
  3. Add the Origin header: Click on “Add header” and add a new header with the key "Origin" and the value of the desired origin domain.

Example:

Key: Origin
Value: https://www.yourdomain.com

3. Using Environment Variables

You can use environment variables to manage Origin headers dynamically, making it easier to test different origins:

  1. Create an Environment variable: In Postman, go to “Environments” and create a new environment or edit an existing one.
  2. Add a variable: Add a variable named “origin” (or any name you prefer) and set its value to the desired origin domain.
  3. Use the variable in the request: In the “Headers” tab of your request, use double curly braces ({{ }}) to insert the environment variable like this: {{origin}}.

Example:

Key: Origin
Value: {{origin}}

Advantages of Using Environment Variables:

  • Dynamic Origins: Easily change origins for different tests without modifying each request.
  • Reusable Logic: Use the same environment variable across multiple requests.

4. Using Pre-Request Scripts

Pre-request scripts allow you to manipulate headers programmatically before a request is sent. This can be useful for more complex scenarios.

Example:

// Get the original origin
const originalOrigin = pm.request.url.protocol + '//' + pm.request.url.host;
// Set the origin header
pm.request.headers.add({
    key: 'Origin',
    value: originalOrigin // Use the original origin
});


// OR
pm.request.headers.add({
    key: 'Origin',
    value: 'https://www.yourdomain.com' // Set a custom origin
});

Why Managing Origin Headers Matters in API Testing

  • CORS Compliance: Many APIs enforce CORS to control access from different origins. The Origin header is crucial for CORS checks.
  • Security: Managing Origin headers helps prevent unauthorized access to your API.
  • Accurate Testing: Setting the correct Origin header ensures your API calls are simulated realistically, reflecting how they would be made in a real-world context.

Impact of Origin Headers on API Testing

Incorrect Origin headers can lead to issues like:

  • CORS Errors: If the Origin header doesn’t match the expected value, you might encounter CORS errors, preventing your requests from being processed.
  • Unauthorized Access: Incorrectly configured Origin headers could allow unauthorized access to your API.

Conclusion

By understanding how Postman handles Origin headers and mastering the methods for managing them, you gain greater control and accuracy in your API testing. This knowledge helps ensure your API calls are secure and compliant, resulting in more comprehensive and effective testing.

API Testing Blog