> For the complete documentation index, see [llms.txt](https://developer.switchmarket.se/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.switchmarket.se/openadr-3/overview.md).

# Overview

Learn more about the OpenADR Virtual Top Node (VTN) that the Switch platform offers as part of its integration possibilities.

The Switch platform exposes a Virtual Top Node (VTN) as defined by the Open Automated Demand Response (OpenADR or OADR) Communications Specification for version 3.0.

This section describes how to use the Switch OpenADR VTN API and its resources. If you have any questions or issues, please contact the [Switch Support](mailto:support@switchmarket.se).

You can find more information about OpenADR 3.0 on the OpenADR Alliance web site [https://www.openadr.org](https://www.openadr.org/).

## VTN Endpoint

The Switch OpenADR VTN can be accessed on two different environments, **Test** and **Production** environment. The VTN can be accessed using the following hostname, depending on the environment:

| Environment | Hostname                  |
| ----------- | ------------------------- |
| Production  | `vtn3.switchmarket.se`    |
| Test        | `qa-vtn3.switchmarket.se` |

{% code title="Example making request" %}

```batch
curl https://vtn3.switchmarket.se
```

{% endcode %}

{% hint style="warning" %}
Note that both environments, Test and Production might have the same or different version of the API deployed. Most of the time the Test environment will have newer version deployed which usually includes new functionalities, optimizations and/or bug fixes.
{% endhint %}