# Manage campaign custom attributes

> In your campaign Settings, you can add campaign custom attributes and set values for them and for any attributes that are mandatory for the Application.

> For the complete documentation index, see [llms.txt](https://docs.talon.one/llms.txt).

## Add custom attributes to a campaign

Adding a custom attribute to a campaign makes it available in the [Attribute Selector](/docs/product/rules/overview.md#attribute-selector)
when creating rules for the campaign.

Before you start, [create one or more custom attributes](/docs/product/account/dev-tools/manage-attributes.md#create-a-custom-attribute)
with `campaign` as their associated entity, and make the attributes available in your Application.

You can then add attributes to your Application:

1. On the left-side menu of your campaign,
   click <Settings className="icon" /> **Settings** > **Custom Attributes**.
1. Click **Add Custom Attribute** to expand the dropdown with the available attributes.
1. Select one or more attributes from the dropdown.
1. Set values for the attributes that you selected by typing the values down.
1. Click **Save Changes**.

## Define values for mandatory attributes

If your Application has [mandatory attributes](/docs/product/applications/use-attributes.md#make-attributes-mandatory),
define values for them before [activating the campaign](/docs/product/campaigns/create-and-manage-campaigns.md#activate-a-campaign).
It is necessary for the campaign to run and its rules to be evaluated.

1. On the left-side menu of your campaign,
   click <Settings className="icon" /> **Settings** > **Custom Attributes**.
1. In **Mandatory attributes**, set values for the required mandatory attributes.
1. Click **Save Changes**.

## Related pages

- [Create templates](/docs/product/campaigns/templates/create-templates.md)
- [Use effects](/docs/product/rules/effects/use-effects.md)