How to Set Up Proxies with Postman (Configuration Tutorial)

October 21, 2023

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Postman has become the tool of choice for API developers and testers for its powerful features that simplify each stage of the API lifecycle. By adding proxy capabilities, Postman unlocks even more potential for secure, stable API testing.

This comprehensive guide will cover everything you need to know about setting up proxies within Postman on different operating systems.

We’ll look at:

Key benefits of using proxies for API testing
An overview of Postman’s core features
Popular proxy service providers that integrate with Postman
Steps to configure system-wide proxies across operating systems
How to set up custom proxy configurations in Postman
Advanced use cases like rotating IPs and handling blocks
Best practices for proxy integration
Troubleshooting common proxy problems
And much more!

Let’s get started.

Why Use Proxies for API Testing?

Proxies act as intermediaries that route traffic between your computer and external servers. Sending your Postman requests through proxy servers provides a number of advantages:

Enhanced Security: Proxies hide your real IP address and scramble request data to provide anonymity. This prevents the API provider from tracing requests back to you.
Bypass Geographic Blocks: Proxies allow you to appear located in a different region to access geo-restricted APIs and services, by routing your traffic through servers in that location.
Rotate IP Addresses: Proxy services give you a large pool of IP addresses that you can dynamically rotate with each request. This helps circumvent IP-based blocks and limits.
Monitor Usage and Costs: Commercial proxy providers offer account dashboards and analytics to track usage across teams and manage expenses.
Increase Success Rates: Strategically combining different proxy types improves reliability in the face of IP blocks and filtering.

Well configured proxies are invaluable for developing, testing, and monitoring APIs while protecting your systems and identity.

Overview of Postman

For the uninitiated, Postman is an API development environment used by over 17 million developers and 100,000+ organizations. It simplifies every phase of working with APIs:

Design and Prototype

Document APIs with OpenAPI specs
Mock servers and endpoints
Develop and visualize collections

Develop and Test

Write scripts with JavaScript
Create dynamic environments
Automated collections
Run performance tests

Collaborate and Monitor

Share collections among teams
Monitor API usage and health
Integrate with CI/CD pipelines
Track changes with version control

Postman is available as a web application as well as native apps for MacOS, Windows, and Linux. We’ll focus on configuring proxies within the Postman desktop app.

Setting Up System Proxy in Postman

If you already have a system-wide proxy configured externally on your machine, Postman can inherit and utilize this for requests by enabling the built-in “Use system proxy” setting.

Here’s how to set it up:

Windows

In Postman, click the wrench icon ⚙️ > Settings > Proxy
Under “Proxy configurations for sending requests”, toggle Use the system proxy to ON.
Check “This proxy requires authentication” and enter your proxy username/password if needed.
Click Save and restart Postman.

MacOS

Go to Postman > Preferences > Proxy
Enable Use the system proxy and enter credentials if required.
Click Save and restart Postman.

Linux

In Postman, go to File > Settings and select Proxy
Toggle on Use the system proxy and add credentials.
Save settings and restart Postman.

Your system proxy is now active!

Enable “Respect system proxy settings for all protocols” to also use system configs for HTTPS, SOCKS, FTP proxies.

Be sure to disable any custom proxies in Postman to prevent conflicts.

Troubleshooting System Proxies

Here are some common problems and solutions:

Authentication Errors – Enable and enter valid credentials under “This proxy requires authentication”.
SSL Errors – Install the Postman CA certificate by running OpenSSL on your machine.
Proxy Not Working – Try rebooting your system and Postman to load the proxy config.
Using default interface – Specify the network interface to use either in Postman or at the system level.

Still having issues? Reach out to your proxy provider's support for assistance.

Setting Up a Custom Proxy in Postman

For more control, you can configure a custom proxy server specifically for Postman independent of your system settings.

Here's how to set up a custom proxy:

In Postman, go to the Proxy tab and make sure Use system proxy is OFF.
Enable Add a custom proxy configuration.
Enter proxy details:
- Proxy Type: HTTP, HTTPS or SOCKS5
- Proxy Server: Hostname like us-pr.brightdata.com
- Port: Proxy port like 22225
- Proxy Auth: Username and password
Click Add to save the proxy server.

You can create multiple custom proxy configs for different providers, auth users, geo locations, etc.

To delete a custom proxy, hover over it and click the trash can icon.

Custom Proxy Tips

Try rotating residential and datacenter proxies to maximize uptime.
Use multiple configurations for different providers, locations, and teams.
Always authenticate with limited-privilege subuser accounts.
Monitor the proxy provider's dashboard to track usage.
Route traffic through less utilized proxy ports to spread volume.

Advanced Proxy Use Cases

Beyond basic setup, there are some more advanced tactics to consider when integrating proxies into your Postman workflows:

Rotating IP Addresses

To avoid IP blocks, you should rotate proxy IP addresses as frequently as possible. Here are some strategies:

Use Postman scripts to pull a new proxy config before each request.
Integrate your provider's API to automate IP cycling.
Create separate Postman configs for each proxy/location.
Rotate IPs at the proxy provider platform level.
Mix IP cycling with hardened residential IPs.

Handling IP Blocks

If your testing does get IPs banned, here are some ways to recover:

Try residential proxies from a different provider.
Route requests through a VPN or private proxy network.
Access the API from a different geographic location.
Slow down request pacing to stay under limits.
Check if the provider offers unblocking services.

Integrating with CI/CD Pipelines

To incorporate proxies into automated pipelines:

Store proxy configurations as environment variables.
Create dedicated subusers for pipeline jobs.
Programmatically fetch new IPs before each run.
Handle proxy failures gracefully within scripts.
Monitor proxy usage to identify bottlenecks.

Additional Authentication Methods

Postman supports alternative proxy authentication schemes:

NTLM: Enter the NTLM domain along with your username and password.
Amazon IAM: Use your AWS access keys.
Azure MSI: Integrate your Azure role credentials.

Refer to your proxy provider's docs for details on usage.

Troubleshooting Common Proxy Problems

No proxy configuration is bulletproof. Here are some common issues and fixes:

Missing Proxy Settings: Update Postman and check that a proxy is set at the system or custom config level.
407 Authentication Required: Enter valid proxy service credentials under system proxy auth or custom proxy settings.
SSL Certificate Issues: Install the Postman CA certificate by running OpenSSL on your operating system.
Gateway Timeout: Your proxy IP may be banned – try rotating to a new residential IP address.
Tunneling Socket Could Not Be Established: Verify the proxy port is open – try toggling between entry ports.
Browser Works But Postman Doesn't: Disable the Postman system proxy and set up a fresh custom proxy config.

Still struggling to get your proxy setup working reliably? Contact your proxy provider's technical support team for troubleshooting assistance.

Best Practices for Postman Proxies

To maximize the effectiveness of proxies, follow these best practices:

Use Multiple Configurations – Set up different proxy configurations to easily switch between various providers, locations, and teams.
Rotate IP Frequently – Cycle proxy IP addresses as often as possible, ideally with each request.
Monitor Usage Closely – Watch for usage spikes that exceed rate limits and get IPs blocked.
Use Proxy-Aware Scripts – Write request code that handles proxies dynamically – auto IP rotating, error handling, etc.
Combine Proxy Types – Blend residential, mobile, and datacenter proxies to improve reliability.
Manage Costs – Analyze proxy expenses so they remain aligned to usage and business value.

Conclusion

Adding proxy capabilities significantly expands Postman's usefulness for secure, stable API testing and development. Both system-wide and custom proxy configurations are straightforward to set up across Windows, MacOS, and Linux.

Carefully monitor usage, frequently cycle IP addresses, leverage multiple providers, and follow the best practices outlined here to maximize the value proxies bring to your Postman API workflows.