> ## Documentation Index
> Fetch the complete documentation index at: https://docs.voucherify.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Introduction

> What is Voucherify API?

The Voucherify API is organized around REST. Our API has predictable, resource-oriented URLs, and uses HTTP response codes to indicate API errors. We use built-in HTTP features, such as HTTP authentication and HTTP verbs, which are understood by off-the-shelf HTTP clients.

We support cross-origin resource sharing, allowing you to interact securely with our API from a client-side web application

<Warning>
  Never expose your secret API key in any public website's client-side code.
</Warning>

JSON is returned by all API responses, including errors. However, Voucherify API libraries convert responses to appropriate language-specific objects.

To make the API as explorable as possible, this documentation has a test mode. You can test all methods at no cost. Click **Try it** in an endpoint page to open a playground and configure your request.

Fields that are necessary in the request are marked as `required`. Fields that will always be returned in the response are also marked as `required`.

In general the API consists of 3 sets:

* **Application API** - full capability, designed to be accessed from your server application
* **Client API** - limited capability, designed to be accessed from your website or mobile application
* **Management API** - endpoints designed to manage Voucherify projects within organization. Enterprise feature only - contact [Voucherify sales team](https://www.voucherify.io/contact-sales "Contact Voucherify Sales") for more details.

<Note>
  Find out more about how to [authenticate your application](/guides/authentication) to access the API.
</Note>