# Custom Headers

Sometimes it is necessary to identify an answer in connection with the request.

For example, you are on a web-page that displays client *account A* information, and you are sending a request in the context of this client *account A*. While your are waiting for the response - which might take "some" time - the user moves on to another client *account B.*

If the response arrives it'll contain the data requested for account A, and you don't want to process this response data any longer because the context has moved to account B.

{% hint style="info" %}
For such use-case, you can use customer headers, which are passed-though from the service. Customer headers start with **`x-custom`**, and whatever you send in the request, it will be in the related response.
{% endhint %}

For example:

```http
GET {{host}}/Docs/query?key=*&UserId=*&Context=*
Authorization: Basic {{basicToken}}
x-custom-boomiaccount: Account A


HTTP/1.1 200 OK
...
x-custom-boomiaccount: Account A
{ ... }
```