The best developers use Postman when dealing with multiple APIs. Learn how this system works in this guide so you can make your own applications!

tutorial creating apis

What is an API?

An application programming interface is a set of standards and programming instructions for using a web-based software or a web tool. Software companies create an API and release it in public. Then, software developers can make products that's based on its service.

An API is not a user interface, but it's a software-to-software interface. With APIs, your applications can talk to each other without user intervention or knowledge.

For example, when you enter your credit information or to buy movie tickets online, the website uses API to send the information to a remote application that determines if the information is valid. Once it confirmed, the remote application would send a response back to the website saying it's okay to distribute the tickets.

What is Postman?

Postman is an API client that allows developers to share, create, document, and test APIs. This allows users to create and save easy and complex HTTP requests and read their responses. This results in less tedious and more efficient work.

The main reason developers use Postman so that they can execute APIs more effectively. Once you’ve learned how to utilize it you’ll increase your value as a junior developer. We'll show you how to do so with this quick postman tutorial!

How to use Postman for API

Using Postman is straightforward and easy to use. Start by going to your Chrome's web apps and click on the Postman logo. Then you'll see Postman's GUI, and you can see the Methods menu (POST, GET, etc.).

On the right side, you can press the ‘SAVE’ button to use your API for later usage.

Variables

There are two variables - environment and global. Global variables are for every request. However, environment variables have been selected from no environment, or a drop down can be selected. Global variables are edited by an eye-shaped icon in the upper right-hand corner.

Once defined, the variables can be used and have a curly bracket: {{Variable Names}}.

Pre Request Scripts

Postman allows users to do Javascript coding to manipulate data that are sent with the request. One example is creating an API - 256 Hash (secretKey + build from the apiKey + timestamp in seconds). Calculating the SHA256 hash is made with a with this pre-request script.

Environments

Code is shown with one group of credentials because they are placed as global variables. If you have to switch between different credentials, then you'll have to use environments. By changing the environment, you can send other parameters to the API.

You can manage your environment from the Settings icon in the upper right-hand corner with the "Manage Environments" link. Postman supports shared environments, which means the team can use the same credentials if it's managed centrally. It requires a plan and a sign in, so it's a good idea for the future.

Closing Remarks

In this postman tutorial, we’ve taught you how to use it’s system so you can utilize your APIs. Doing so allows you to shift between different APIs faster and use them with other coders within your network. After learning more about it, you’ll be able to make complex algorithms in no time!

Do you have any additional questions on how to use Postman?

Tell us in the comments below.

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About the author

Alex Roman

Independent graphic artist and architect based in Bucharest. I really love what i do!

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