# Flex API Getting Started

Ixkio's Flex API plan is designed for for verification of NTAG424 authentication tags via API. Trusted by some of the world's largest brands, the Ixkio Flex API authentication platform provides an easy to use, fast, reliable and scaleable platform for auth tag projects.&#x20;

Ixkio also supports the encoding of NTAG424 tags via the ixkio mobile app for use with the Flex API plan.&#x20;

Use of the API system requires a strong understanding of technical knowledge and the ability to access and develop your webserver at an in-depth level. Ixkio cannot give advice on setting up or the configuration of your server beyond advising how our server would respond to an API call. If you aren't technically minded or don't have access to technical developers, we'd recommend using our Flex Pro plan with Redirect or Direct Response.&#x20;

{% hint style="info" %}
These pages details how to use the **Flex API** to verify your authentication tag scans.&#x20;

If you are looking to use the **Management API** to modify Tag Codes, then read about [Management API](https://docs.ixkio.com/advanced-features/management-api).&#x20;
{% endhint %}

### Typical Use Case

In all cases, the authentication NFC tag will link directly to your webserver or application, rather than linking directly to the ixkio platform. In other words, you can't use ixkio as a redirect and API platform for the same tag.&#x20;

Where the tags are linked to a website, your webserver would extract the query string parameters from the URL and then make a GET request with those parameters to our server. The ixkio server will check the parameters and respond with a pass or fail message.

Your server can then respond directly to the user with the appropriate message.

### API Overview

The ixkio Response API system is designed to be easy to use and access. &#x20;

* Flex API can only be used to extract tag information, not set, create or change it
* Rules can be used to set and control the API response
* API responses can also include additional information
* All API requests must be on `https` not `http`
* Access to API can be open or controlled with an API Key
* Flex API supports a range of NTAG424 encoding options, including :&#x20;
  * CMAC only encoding
  * CMAC and PICCData (Meta) encoding with multiple keys
  * CMAC and PICCData (Meta) encoding with diversified keys
* NTAG424 tags can be encoded directly to the ixkio platform - using your destination domain - using our ixkio app if required.&#x20;