Twilio SendGrid Marketing Campaigns Custom Fields API

The Twilio SendGrid Marketing Campaigns Custom Fields API allows you to add extra information about your marketing contacts that is relevant to your needs. For example, a fashion retailer might create a custom field for customers' shoe sizes, an ice cream shop might store customers' favorite flavors in a custom field, and you can create custom fields that make sense for your business.With custom fields, you can also create [segments](https://docs.sendgrid.com/api-reference/segmenting-contacts-v2/) based on custom fields values. Your custom fields are completely customizable to the use-cases and user information that you need.You can also manage your Custom Fields using the SendGrid application user interface. See [**Using Custom Fields**](https://docs.sendgrid.com/ui/managing-contacts/custom-fields) for more information, including a list of Reserved Fields. You can also manage your custom fields in the [Marketing Campaigns application user interface](https://mc.sendgrid.com/custom-fields).