Product, growth and marketing-operations teams use Postman to try out APIs long before anything reaches a customer. Many of those APIs answer differently by region: a pricing endpoint returns a local currency, a content API serves a regional catalogue, a store locator lists nearby branches. To test that behaviour properly, the request has to arrive from the region in question. Sending Postman's traffic through a proxy does that without anyone leaving the office.
Regional questions a proxy helps answer
- Does our pricing API return the right currency and tax display in each market?
- Does the catalogue or content API serve the correct regional version?
- Are the geo-restrictions on our own endpoints set up the way the business intended?
- Does a partner API we are authorised to use respond correctly for traffic from a given country?
What to gather first
Work in the Postman desktop app. The proxy options described here belong to it, and the browser version cannot reliably use a proxy configured on your computer. You also need your proxy credentials. Our proxies arrive in HOST:PORT form with a username and password, so note four values:
- Host, for example
gateway.example-proxy.com - Port, for example
8080 - Username and Password
For API testing, where a steady connection matters more than a changing address, datacenter proxies are usually the sensible choice. When a test must come from a home broadband connection, use residential proxies. All four types are described on the proxies overview, and plans are on the pricing page.
Setting up the desktop app
Reach the Proxy tab
- Settings sits behind the gear icon in Postman's top-right corner. Keyboard users can jump there with
Ctrl+,on Windows and Linux, orCmd+,on macOS. - Choose Proxy from the list on the left.
The tab offers two routes. Use the system proxy borrows whatever proxy the operating system already has, while Add a custom proxy configuration gives Postman settings of its own. For regional testing, the custom route gives you precise control.
Fill in your own configuration
- Switch on Add a custom proxy configuration.
- Keep both HTTP and HTTPS ticked under Proxy Type, so every request goes through the proxy.
- Next to Proxy Server, enter the host as the address and the port number in the field beside it, for example
gateway.example-proxy.comand8080. - Enable Proxy auth; the username and password boxes appear below it.
- Type in the Username and Password.
Postman stores the values as you type, so there is nothing to save.
Certificate warnings during tests
Depending on your network, Postman may report certificate verification problems once traffic is proxied. When the proxy is one you trust and those errors stop a test, look in the General tab of Settings for the SSL certificate verification switch. Turn it off for that test only and back on afterwards. It is a testing convenience, not a security setting to leave disabled.
First request: confirm the exit IP
Create a GET request to an address that echoes the caller's IP, such as https://api.ipify.org?format=json, and press Send. The response should show the proxy's exit address rather than your office's. Cross-check the address in our my IP tool, or run the endpoint through the proxy checker on its own.
Proxying one collection only, with Newman
Postman's in-app proxy applies to every request. When only one collection should use it, run that collection with Newman instead. Newman is the command-line runner for Postman collections, and it picks up the usual proxy environment variables. In Windows PowerShell:
$env:HTTPS_PROXY = "http://USER:PASS@HOST:PORT"
$env:HTTP_PROXY = "http://USER:PASS@HOST:PORT"
newman run my-collection.jsonAnd on macOS or Linux:
export HTTPS_PROXY="http://USER:PASS@HOST:PORT"
export HTTP_PROXY="http://USER:PASS@HOST:PORT"
newman run my-collection.jsonSwap in your real credentials for USER, PASS, HOST and PORT. The variables apply to that Newman process alone, so proxied and direct collections can run side by side. The same commands can go into a CI pipeline, giving each release a regional check.
When requests misbehave
| Symptom | Likely fix |
|---|---|
| 407 Proxy Authentication Required | Usually the credentials. Re-enter them, watching for spaces picked up when pasting, and confirm that Proxy auth is ticked. |
| Requests time out | Recheck the host and port first. If they are right, an office or local firewall may be blocking the outbound port; the proxy checker shows whether the endpoint itself responds. |
| Some requests skip the proxy | Two settings are competing. Turn off Use the system proxy and leave the custom configuration as the only one. |
| The wrong region comes back | If location is chosen through parameters in the username, copy the username exactly as the documentation shows it. |
Sharing the setup across a team
- If several testers work from one office, consider IP-whitelist authentication, set in your dashboard. Requests from the whitelisted office address need no password, so leave Proxy auth unticked and no login circulates around the team.
- Write the host and port into the team's test documentation, so every tester points Postman at the same market.
- Proxied requests count towards the order's data like any other traffic, which keeps the cost of API testing easy to follow.
Testing within the rules
Point a proxied Postman at your own APIs, or at third-party APIs your company has permission to call, and nothing else. Respect each service's rate limits and terms; the proxy alters where a request appears to originate, not what an API's usage policy permits.
With host, port, username and password filled in, every request takes the route you chose. For regular regional testing, keep a few market endpoints saved, switch between them as the work requires, and confirm each one with a fresh IP check.
