Environment variables in Postman

Introduction

Environment variables help you store and reuse values like URLs or tokens easily. They make tests simpler and faster to update.

When you want to run the same test on different servers like development, testing, and production.

When you need to keep sensitive data like API keys safe and separate from your test scripts.

When you want to avoid repeating the same value in many places in your tests.

When you want to quickly change a value used in many requests without editing each one.

When you want to share common data across multiple requests or collections.

Syntax

Postman

pm.environment.set("variable_key", "value");
pm.environment.get("variable_key");
pm.environment.unset("variable_key");

Use pm.environment.set to create or update a variable.

Use pm.environment.get to read a variable's value.

Use pm.environment.unset to remove a variable.

Examples

Sets the environment variable baseUrl to the API URL.

Postman

pm.environment.set("baseUrl", "https://api.example.com");

Gets the value of the authToken variable to use in a request.

Postman

const token = pm.environment.get("authToken");

Removes the variable tempData from the environment.

Postman

pm.environment.unset("tempData");

Sample Program

This script sets an environment variable userId, retrieves it, prints it, and checks if it equals "12345".

Postman

// Set environment variable
pm.environment.set("userId", "12345");

// Get and print environment variable
const userId = pm.environment.get("userId");
console.log(`User ID is: ${userId}`);

// Use environment variable in a test
pm.test("User ID should be 12345", function () {
    pm.expect(userId).to.eql("12345");
});

Important Notes

Environment variables are case-sensitive.

Always clear variables you no longer need to avoid confusion.

You can manage environment variables in Postman's UI under the Environment quick look.

Summary

Environment variables store reusable values for your tests.

They help run tests easily on different setups without changing code.

Use Postman scripts to set, get, and remove these variables.