# Introduction

We will use Postman to demonstrate how to get started with the Real Items API.

{% hint style="info" %}
You can find detailed information about individual API functions, examples, and more in the Real Items API Postman collection: [postman-documentation](https://docs.realitems.io/realitems-api/resources/postman-documentation "mention")
{% endhint %}

### Authentication

Your API requests are authenticated using an API key. Your API key must be passed as an HTTP header in each request. Any request that doesn't include a valid API key will return an error.

To get an API key, you need to have a subscription.

{% content-ref url="../account/subscribe-to-a-plan" %}
[subscribe-to-a-plan](https://docs.realitems.io/realitems-api/account/subscribe-to-a-plan)
{% endcontent-ref %}

{% hint style="info" %}
Store your API key somewhere safe (like a password manager). Be prepared to access your API key easily as you will be using it later in this tutorial.
{% endhint %}

Once you have your API key, you're ready to fork the Real Items API Postman collection.