# User-Agent

To identify who the calling application is please provide the User-Agent Header to the API

> **In 2027** all developers using our API is required to send the **User-Agent** Header so we can identify who the calling application is.


If this header is not sent to the server we will return **400 - Bad Request**

Please adjust your code to prepare for this **Breaking Change**


**Example:**

If you are using our API to sync data to your ERP system you can write **dynamics-365**

![Postman-User-Agent](/assets/image-4.63de5bf55492d6396dd46fe5daf4e8b4c26ee877d4c05c717c5aaf7c776aa48b.9817d8cf.png)