Postman is a versatile tool that allows developers and testers to streamline their API workflows. One of the key features that make Postman so powerful is the ability to use variables—both environment and global. Understanding these variables will help you manage your APIs more efficiently and avoid repetitive tasks.

What are Environment Variables?

Environment variables in Postman are specific to a workspace, which means they can be used across requests within that workspace. They allow you to store different values for different environments (e.g., development, testing, production). For instance, you may want to use a different API URL in your development environment than in production.

How to Create Environment Variables:

1. Create a New Environment:

   • Open Postman and go to the top right corner.
   • Click on the Environment Quick Look (eye icon).
   • Select Manage Environments.
   • Click on Add to create a new environment.
   • Give it a name (e.g., "Development").

2. Add Variables:

   • With your new environment selected, start adding variables.
   • Define a key (name) and a corresponding value (like API_URL and https://api.dev.example.com).
   • Click on Add to save.

3. Using Environment Variables in Requests:

   • To reference an environment variable within a request URL or body, use the syntax {{API_URL}}. Postman will replace it with the corresponding value based on the selected environment.

What are Global Variables?

Global variables are accessible from anywhere in Postman, making them ideal for values you need to use across multiple environments or requests. They are perfect for constants that don’t change between environments, like API keys or standard headers.

How to Create Global Variables:

1. Open Global Variables:

   • Click on the Environment Quick Look (eye icon) on the top right.
   • Scroll down to the Globals section.

2. Add Global Variables:

   • Click on Edit beside Globals.
   • Add key-value pairs (e.g., API_KEY and 12345).
   • Click on Save.

3. Using Global Variables in Requests:

   • Similar to environment variables, you can reference a global variable using {{API_KEY}} anywhere in your requests.

Switching Environments

To switch between environments, simply go to the Environment Quick Look and select the desired environment from the dropdown. This allows you to work seamlessly between different setups without manually changing variable values.

Advantages of Using Variables

• Efficiency: Using variables can reduce redundancy and simplify your requests.
• Maintainability: Changes to variable values are automatic across all requests using those variables, making updates easier.
• Clarity: Variables help separate different configurations, making it easier to understand and manage your API calls based on the current context.

Managing Variables

To manage or delete existing variables, go back to the environment or global management interface where you created them. From here, you can edit or remove entries as needed. Always ensure to keep your variables organized, especially when working with multiple environments or complex projects.

By leveraging environment and global variables in Postman, you can streamline your API testing process and enhance your productivity. Use these tools to make your workflows cleaner and automated!