# Custom Header

The Custom Header feature allows you to add, modify, or remove HTTP headers for both origin requests and CDN responses. This configuration enables fine-grained control over how headers are passed, overwritten, or stripped at different stages of the delivery flow.

When Custom Header is enabled, you can define multiple header actions, each with a specific key–value pair and rule type. All rules are executed by CDN edge servers for the selected CDN Resource.

You can configure Custom Header in the [Medianova Control Panel](https://cloud.medianova.com) or via [API](https://clients.medianova.com/api-documentation/performance-cdn/headers#put-api-v1-cdn-organization_uuid-resource-resource_uuid-1)

## Configure Custom Header

{% stepper %}
{% step %}
**Access Custom Header**

Go to **CDN → CDN Resources** and select a CDN Resource.\
Scroll to the **Custom Header** section.
{% endstep %}

{% step %}
**Enable Custom Header**

<figure><img src="/files/1InO4ysXwaNikFmm2tuF" alt="" width="563"><figcaption><p>Custom Header configuration interface in the Headers tab</p></figcaption></figure>

Toggle **Status** to enable the Custom Header feature.\
Verify that the rule configuration area becomes active.
{% endstep %}

{% step %}
**Create Custom Header Rules**

Select a header action from the dropdown.

**Available Header Actions**\
You can create header rules using the Add dropdown.\
Each option applies to a different stage of the request/response flow.\
**Add Origin Request Header**\
Adds a custom header to the request sent from CDN edge to the origin server.\
**Add CDN Response Header**\
Adds a custom header to responses delivered from CDN edge to the viewer.\
**Remove CDN Response Header**\
Removes a header from the response before it is sent to the viewer.\
**Raw Header**\
Creates a raw header rule with a custom directive, without binding it to request or response type logic. (Use only if you require fully custom header behavior.)\
**Remove Origin Request Header**\
Removes a header before the request is forwarded to the origin server.

Enter the **Key** and **Value** for the header, if the selected action requires one.<br>
{% endstep %}

{% step %}
**Select Submit to save**
{% endstep %}
{% endstepper %}

## Best Practices

* Header keys and values must follow valid HTTP header formatting rules.
* If the same header is modified by multiple rules, CDN edge behavior follows the order of applied rules.
* Removing headers may affect origin authentication, CORS behavior, or cache control logic.
* Use **Raw Header** only when standard rule types do not fit your use case.


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