How to Configure a Postman Proxy

Postman is a platform for building and managing APIs. It enables users to create, test, document, and publish APIs within a single interface. It also significantly simplifies the workflow for developers and QA engineers by offering tools for automation, collaboration, and monitoring. To safeguard your work, it’s recommended to configure a Postman proxy server. It helps secure data transfers and reduce exposure to potential risks.

Video tutorial for proxy configuration in Postman

What Are The Benefits of Using a Postman Proxy Server?

Such servers are crucial resources for stress-testing an API during development since they enable several viewpoints to be applied to the API. By employing a wide range of residential, ISP, and Mobile intermediate connections, developers may verify that the API works as intended while connecting with different addresses.

You can determine whether an API provides the correct conditional response for a specific region by testing geolocation behavior. By using a Postman proxy, developers can manage how many requests their apps can handle simultaneously and simulate various use cases.

Using Postman’s integration with connection tools provides the following combined benefits of both the platform and their use:

• Response Inspection: By recording server answers, it makes it easier to analyze API data.
• API Discovery: It helps identify undocumented APIs by monitoring network traffic.
• Debugging API Integrations: Check the transmitted data and resolve issues.
• Request Capture: After intercepting client requests, it displays the exact data being sent.
• Documenting Undocumented APIs: Reverse-engineer API endpoints to create accurate documentation.
• Testing Mobile Applications: Record and examine API requests made by mobile applications.
• Improved Security: Intermediary servers mask your IP address and secure request data to enhance privacy.
• Regional Routing: Servers located in different countries enable testing API responses under various regional conditions and connectivity settings.
• Rotate IP Addresses: A large pool of IP addresses may be dynamically rotated with each request in Postman.

How to Add Proxy in Postman: Step-by-Step Tutorial

By adding it, you can enhance privacy by substituting intermediary connection data for the information associated with your public IP.

System Settings

This configuration ensures that all queries made via the platform use the server connected to your device previously. Either with system OS settings, or with other softwares, like Proxifier.

1. After launching the desktop application, at the top of the window, click the gear icon. From the menu that appears, choose Settings.

2. Select the Proxy tab, then confirm that the Use system proxy option is enabled.

Once you have confirmed that the parameters are correct, this configuration ensures that all queries made via the platform use the intermediary connected to your device.

Custom Proxy Settings

After this setting, all API calls will be redirected using our configuration. In the meanwhile, the rest of your internet connection will either travel straight to your ISP or via your system network. Also, make sure to check the difference between paid and free proxy servers. This is how you do it:

1. Turn the Use custom proxy configuration option on.

2. Enter Details:

• Choose the type between HTTP and HTTPS.
• Enter a new IP address that was given to you by a provider.
• Specify which port is used by the intermediate server.

• Make sure to enter all authentication details if your intermediary is a private one.

3. Save and Restart:

To use the updated settings, click Save and restart the app.

Common Postman Proxy Issues & Fixes

Here are a few typical problems and solutions:

• 407 Authentication Error: Ensure you’ve entered the correct username and password
• SSL Certificate Problems: Installing the Postman CA certificate on your PC requires that you use OpenSSL.
• Gateway Timeout: This may indicate that the assigned IP is unstable or temporarily limited. Switching to a more reliable ISP proxy connection can help.
• No Tunneling Socket Could Be Found: To verify the gateway port, try adjusting the port configuration.
• Postman proxy not working: If the connection fails to connect while your browser functions normally, disable system settings and manually configure a custom setup.

Troubleshooting Request Issues in Postman

Possible issue: Unable to send a request when the network requires a proxy.

Ensure your operating system is properly configured and that Postman is set to use the system’s network route.

• On Windows, go to Settings → Network & Internet, scroll to Manual setup, enable the toggle, and enter the relay address and port. Click Save.
• On macOS, open System Preferences → Network, select your active connection, click Advanced, then go to the Proxies tab. Check Web Proxy (HTTP), enter the intermediary address and port, and provide credentials if needed. Confirm by clicking OK and then Apply.
• On Linux, the steps may vary by distribution. Navigate to Settings → Network, then enable the network routing method (automatic or manual) and enter your connection parameters.

Possible issue: Unable to send a request when no proxy is required by the network.

1. Check that Postman’s system-based and custom relay options are both turned off.
2. Click the gear icon in the top right to open Settings → Proxy. Make sure both Use system configuration and Use custom setup are disabled.

If the issue persists, system environment variables might override Postman’s internal networking settings. To resolve this, remove variables such as http_proxy, https_proxy, HTTP_PROXY, and HTTPS_PROXY from your OS or shell profile. Alternatively, create a launcher script to start Postman in a clean environment.

• Windows - Use the following code to create a postman.bat file:

  

• macOS or Linux - Make a postman.sh file in Linux or macOS using the code below:

  

Possible issue: The system proxy requires basic authentication.

If your relay server needs credentials, enable basic authentication directly in the desktop app. Ensure the correct username and password are entered in the custom connection settings. You can also launch an app with authentication parameters through a startup script if your system requires it.

• Windows – Use the following code to create a postman.bat file:

  

• macOS or Linux – Create a postman.sh file with the following code:

  

Postman Proxy Settings: Final Thoughts

Configuring a network relay in Postman allows routing API requests through remote endpoints, integrating traffic control directly into your collections. For more control, the Proxy Bypass feature allows overriding default connection settings per request, ideal for cases where specific API calls need individual routing behavior.

Postman is a ground-breaking tool for API development that makes it easier to design, test, and deploy APIs. Regardless of your level of development experience, Postman's user-friendly user interface and gateway settings provide invaluable support throughout the whole API lifecycle.

A proxy is a flexible solution that enables extensive testing, ensuring APIs operate reliably and securely even under challenging real-world conditions. Read also how to set up a new secure connection using proxy in Brave Browser.